JP2007263187A - Control device for automatic transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission, capable of securing travelling performance while avoiding an interlocked condition even if the interlocked condition is generated. <P>SOLUTION: The control device for the automatic transmission comprises an interlocked condition detecting means for detecting the interlocked condition in which one of fastening elements fails in fastening and the rotation of an input rotating element and that of an output rotating element are fixed, an avoidance determining means for releasing one of the fastening elements which achieves a command shift stage at the time when the interlocked condition detecting means detects the interlocked condition and for determining whether a shift stage on a higher speed side than a predetermined shift stage is achieved as an avoidance shift stage from the command shift stage at the time when detecting the interlocked condition, and a failure shift control means for shifting the shift stage to the avoidance shift stage when the avoidance determining means determines that it can be achieved, or otherwise for releasing all fastening elements into a neutral condition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic transmission, and more particularly to control for avoiding an interlock state due to a fastening failure of a fastening element.

As a control for avoiding the interlock state of the automatic transmission, a technique described in Patent Document 1 is disclosed. In this publication, in order to detect a stick of a valve that controls the hydraulic pressure of the friction element, a signal pressure operation valve is provided that operates when even one abnormality occurs in the supply hydraulic pressure of each friction element. A hydraulic switch is provided on the downstream side of this signal pressure valve, and when a change in the downstream oil pressure is detected by the hydraulic switch due to the operation of the signal pressure valve, all hydraulic pressures are reduced to a neutral state to avoid an interlock state. is doing.
JP 2003-49937 A.

  By the way, in recent years, the number of transmissions has increased, and the number of planetary gears and the number of friction elements such as clutches and brakes have increased in accordance with the number of gears. For this reason, when a plurality of signal pressure actuating valves and signal pressure hydraulic switches are provided in the hydraulic circuit of friction elements that should not be simultaneously engaged as in the above prior art, the number of parts increases, the control valve body As a result, it has become a manufacturing issue.

Further, since no particular consideration is given to which friction element is a failure, there is a problem that a neutral state has to be set, and traveling performance after the failure cannot be ensured. That is, in the above prior art, although the interlock state itself is avoided, there is a possibility that the driving force is insufficient or cannot be secured when restarting after stopping, and there is a problem that the running performance at the time of failure greatly deteriorates. is there.

  The present invention has been made paying attention to the above problems, and it is an object of the present invention to provide a control device for an automatic transmission that can ensure traveling performance while avoiding the interlock state even if the interlock state occurs. To do.

  In order to achieve the above object, in the automatic transmission control device of the present invention, an input rotation element connected to a power source, an output rotation element connected to a drive wheel, and a planetary gear train having a plurality of rotation elements, , Fastening / release between the rotating elements, or a plurality of fastening elements for selectively stopping the rotating elements, and determining a command shift stage based on a running state, and executing a fastening / release control law for the fastening elements And a shift control means for detecting an interlock state in which one of the fastening elements is faulty and the rotation of the input rotating element and the rotation of the output rotating element are fixed. When the interlock state is detected by the lock state detection means and the interlock state detection means, one of the fastening elements that achieves the command shift stage at this time is released, thereby causing a predetermined speed change. If it is determined by the avoidance determination means that the shift speed on the higher speed side can be achieved as the avoidance shift speed from the command shift speed at the time when the interlock state is detected, And a failure-time shift control means for shifting to the avoidance shift stage and setting to a neutral state at other times.

  Therefore, in the automatic transmission control device of the present invention, when the interlock state is detected, is it possible to achieve an avoidance shift speed higher than the predetermined shift speed by releasing one normal fastening element? Judgment is made based on the instruction gear position at the time of failure detection, and if it can be achieved, only one fastening element is released, so that the interlock state is surely avoided and a significant downshift is involved. Therefore, it is possible to obtain a driving force without fail and to ensure traveling performance. In addition, when it is possible to achieve an avoidance shift stage that is equal to or higher than a predetermined shift stage by releasing one normal engagement element, the neutral state is set, so that the interlock state is reliably avoided and a significant downshift is possible. Occurrence can be avoided and safety can be ensured.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for realizing an automatic transmission control apparatus according to the present invention will be described below based on embodiments shown in the drawings.

  FIG. 1 is a skeleton diagram showing the configuration of an automatic transmission that achieves the first forward speed and the reverse speed of the FR type according to the first embodiment, and an overall system diagram showing a control configuration of the automatic transmission. The automatic transmission according to the first embodiment is connected to an engine Eg (corresponding to a power source described in claims) via a torque converter TC to which a lockup clutch LUC is attached. The rotation output from the engine Eg rotationally drives the pump impeller and the oil pump OP of the torque converter TC. The oil stirred by the rotation of the pump impeller is transmitted to the turbine runner via the stator, and drives the input shaft Input (corresponding to the input rotation element described in the claims).

  In addition, an engine controller (ECU) 10 that controls the drive state of the engine Eg, an automatic transmission controller (ATCU) 20 that controls the shift state of the automatic transmission, and the hydraulic pressure of each fastening element based on the output signal of the ATCU 20 A control valve unit CVU that performs control is provided. The ATCU 20 and the control valve unit CVU correspond to the shift control means. The ECU 10 and the ATCU 20 are connected via a CAN communication line or the like, and share sensor information and control information with each other by communication.

  An ECU 10 is connected to an APO sensor 1 that detects the driver's accelerator pedal operation amount and an engine speed sensor 2 that detects the engine speed. The ECU 10 controls the fuel injection amount and the throttle opening based on the engine speed and the accelerator pedal operation amount, and controls the engine output speed and the engine torque.

  The ATCU 20 includes a first turbine rotation speed sensor 3 that detects the rotation speed of a first carrier PC1, which will be described later, a second turbine rotation speed sensor 4 that detects the rotation speed of the first ring gear R1, and an output shaft Output. Are connected to an output shaft speed sensor 5 for detecting the number of revolutions) and an inhibitor switch 6 for detecting the shift lever operating state of the driver. , N and D, an engine brake range position where the engine brake acts and a normal forward travel range position where the engine brake does not act are provided.

  In the ATCU 20, together with a rotation speed calculation unit for calculating the rotation speed of the input shaft Input, an optimum command shift stage is selected from a shift map of the seventh forward speed stage, which will be described later, based on the vehicle speed Vsp and the accelerator pedal opening APO. The control valve unit CVU is provided with a shift control unit that outputs a control command for achieving the command shift speed. The configuration of the rotation speed calculation unit will be described later.

(About automatic transmission configuration)
Next, the configuration of the automatic transmission will be described. The first planetary gear set GS1 and the second planetary gear set GS2 are arranged in this order from the input shaft Input side to the axial output shaft Output side. In addition, a plurality of clutches C1, C2, C3 and brakes B1, B2, B3, B4 are arranged as friction engagement elements. A plurality of one-way clutches F1 and F2 are arranged.

  The first planetary gear G1 is a single pinion type planetary gear having a first sun gear S1, a first ring gear R1, and a first carrier PC1 that supports a first pinion P1 that meshes with both gears S1, R1.

  The second planetary gear G2 is a single pinion type planetary gear having a second sun gear S2, a second ring gear R2, and a second carrier PC2 that supports a second pinion P2 that meshes with both gears S2 and R2.

  The third planetary gear G3 is a single pinion type planetary gear having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a third pinion P3 that meshes with both gears S3 and R3.

  The fourth planetary gear G4 is a single pinion type planetary gear having a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier PC4 that supports a fourth pinion P4 that meshes with both gears S4 and R4.

  The input shaft Input is connected to the second ring gear R2 and inputs the rotational driving force from the engine Eg via the torque converter TC or the like.

  The output shaft Output is connected to the third carrier PC3, and transmits the output rotational driving force to the driving wheels via a final gear or the like not shown.

  The first connecting member M1 is a member that integrally connects the first ring gear R1, the second carrier PC2, and the fourth ring gear R4.

  The second connecting member M2 is a member that integrally connects the third ring gear R3 and the fourth carrier PC4.

  The third connecting member M3 is a member that integrally connects the first sun gear S1 and the second sun gear S2.

  The first planetary gear set GS1 is configured by connecting a first planetary gear G1 and a second planetary gear G2 by a first connecting member M1 and a third connecting member M3, and is composed of four rotating elements. The second planetary gear set GS2 is composed of five rotating elements in which the third planetary gear G3 and the fourth planetary gear G4 are connected by a second connecting member M2.

  The first planetary gear set GS1 has a torque input path that is input from the input shaft Input to the second ring gear R2. The torque input to the first planetary gear set GS1 is output from the first connecting member M1 to the second planetary gear set GS2.

  The second planetary gear set GS2 has a torque input path that is input from the input shaft Input to the second connecting member M2, and a torque input path that is input from the first connecting member M1 to the fourth ring gear R4. The torque input to the second planetary gear set GS2 is output from the third carrier PC3 to the output shaft Output.

  When the H & LR clutch C3 is released and the rotation speed of the fourth sun gear S4 is larger than that of the third sun gear S3, the third sun gear S3 and the fourth sun gear S4 generate independent rotation speeds. Therefore, the third planetary gear G3 and the fourth planetary gear G4 are connected via the second connecting member M2, and each planetary gear achieves an independent gear ratio.

  The input clutch C1 is a clutch that selectively connects and disconnects the input shaft Input and the second connecting member M2.

  The direct clutch C2 is a clutch that selectively connects and disconnects the fourth sun gear S4 and the fourth carrier PC4.

  The H & LR clutch C3 is a clutch that selectively connects and disconnects the third sun gear S3 and the fourth sun gear S4. A second one-way clutch F2 is arranged between the third sun gear S3 and the fourth sun gear.

  The front brake B1 is a brake that selectively stops the rotation of the first carrier PC1. The first one-way clutch F1 is disposed in parallel with the front brake B1.

  The low brake B2 is a brake that selectively stops the rotation of the third sun gear S3.

  The 2346 brake B3 is a brake that selectively stops the rotation of the third connecting member M3 (the first sun gear S1 and the second sun gear S2).

  The reverse brake B4 is a brake that selectively stops the rotation of the fourth carrier PC4.

(About turbine speed calculation)
Paying attention to the fact that the input shaft Input is connected to the second ring gear R2, and the first planetary gear G1 and the second planetary gear G2 constitute a first planetary gear set GS1 in which two rotating elements are connected. In the rotation speed calculation unit provided in, the rotation speed of the input shaft Input is detected by calculation using the two turbine rotation speed sensors 3 and 4.

Specifically, the rotation speed of the first carrier PC1 is N (PC1), the rotation speed of the second carrier PC2 is N (PC2), and the rotation speed of the second ring gear R2 is N (R2). As shown in the figure, the gear ratio between the second ring gear R2 and the second carrier PC2 (first ring gear R1) is 1, and the gear ratio between the first ring gear R1 (second carrier PC2) and the first carrier PC1 is β. , The following formula,
N (R2) = (1 + 1 / β) N (PC2) − (1 / β) · N (PC1)
Is calculated by

  The first turbine rotational speed sensor 3 detects the rotational speed of the second carrier PC2, and the second turbine rotational speed sensor 4 detects the rotational speed of the sensor member 63 as a turbine sensor member connected to the first carrier PC1. To do. Thereby, the rotation speed of the second ring gear R2 (input shaft Input) (hereinafter referred to as turbine rotation speed) is detected by calculation based on the above formula.

(About the configuration of the control valve unit)
FIG. 2 is a circuit diagram showing a hydraulic circuit of the control valve unit CVU. The circuit configuration will be described below. The hydraulic circuit according to the first embodiment includes an oil pump OP as a hydraulic source driven by an engine, a manual valve MV that switches an oil passage that supplies a line pressure PL in conjunction with a driver's shift lever operation, and a line A pilot valve PV for reducing the pressure to a predetermined constant pressure is provided.

  In addition, a first pressure regulating valve CV1 for regulating the engagement pressure of the low brake B2, a second pressure regulating valve CV2 for regulating the engagement pressure of the input clutch C1, a third pressure regulating valve CV3 for regulating the engagement pressure of the front brake B1, A fourth pressure regulating valve CV4 that regulates the engagement pressure of the H & RL clutch C3, a fifth pressure regulation valve CV5 that regulates the engagement pressure of the 2346 brake B3, and a sixth pressure regulation valve CV6 that regulates the engagement pressure of the direct clutch C2 are provided. Yes.

  In addition, either the first switching valve SV1, which switches the low brake B2 or the input clutch C1 to the state where only one of the supply oil passages is in communication, or the supply oil passage for the D range pressure and R range pressure for the direct clutch C2. A second switching valve SV2 that switches to a state that only communicates, and a third switching valve SV3 that switches the hydraulic pressure supplied to the reverse brake B4 between the hydraulic pressure supplied from the sixth pressure regulating valve CV6 and the hydraulic pressure supplied from the R range pressure. And the 4th switching valve SV4 which switches the hydraulic pressure output from 6th pressure regulation valve CV6 between the oil path 123 and the oil path 122 is provided.

  Further, based on a control signal from the automatic transmission control unit 20, a first solenoid valve SOL1 that outputs a pressure regulation signal to the first pressure regulation valve CV1, and a second pressure regulation signal that is output to the second pressure regulation valve CV2. 2 solenoid valve SOL2, 3rd solenoid valve SOL3 that outputs pressure regulation signal to 3rd pressure regulation valve CV3, 4th solenoid valve SOL4 that outputs pressure regulation signal to 4th pressure regulation valve CV4, and 5th pressure regulation valve 5th solenoid valve SOL5 that outputs pressure regulation signal to CV5, 6th solenoid valve SOL6 that outputs pressure regulation signal to 6th pressure regulation valve CV6, and switching to 1st switching valve SV1 and 3rd switching valve SV3 A seventh solenoid valve SOL7 that outputs a signal is provided.

  Each of the solenoid valves SOL2, SOL5, SOL6 is a three-way proportional solenoid valve having three ports, the first port is supplied with pilot pressure described later, the second port is connected to a drain oil passage, Each port is connected to a pressure receiving portion of a pressure regulating valve or a switching valve. The solenoid valves SOL1, SOL3, and SOL4 are two-way proportional solenoid valves having two ports, and the solenoid valve SOL7 is a three-way on / off solenoid valve having three ports.

  The first solenoid valve SOL1, the third solenoid valve SOL3, and the seventh solenoid valve SOL7 are normally closed types (closed when not energized). On the other hand, the second solenoid valve SOL2, the fourth solenoid valve SOL4, the fifth solenoid valve SOL5, and the sixth solenoid valve SOL6 are of a normally open type (open state when not energized).

(About oil passage configuration)
The discharge pressure of the oil pump OP driven by the engine is adjusted to the line pressure and then supplied to the oil passage 101 and the oil passage 102. The oil passage 101 includes an oil passage 101a connected to a manual valve MV that operates in conjunction with the driver's shift lever operation, an oil passage 101b that supplies the original pressure of the fastening pressure of the front brake B1, and an H & LR clutch C3. An oil passage 101c for supplying the original pressure of the fastening pressure is connected.

  The manual valve MV is connected to an oil passage 105 and an oil passage 106 that supplies an R range pressure selected during reverse travel, and switches between the oil passage 105 and the oil passage 106 in accordance with a shift lever operation.

  In the oil passage 105, there are an oil passage 105a that supplies the original pressure of the engagement pressure of the low brake B2, an oil passage 105b that supplies the original pressure of the engagement pressure of the input clutch C1, and an original pressure of the engagement pressure of the 2346 brake B3. An oil passage 105c for supplying, an oil passage 105d for supplying the original pressure of the engagement pressure of the direct clutch C2, and an oil passage 105e for supplying a switching pressure of a second switching valve SV2 described later are connected.

  In the oil passage 106, an oil passage 106a that supplies the switching pressure of the second switching valve SV2, an oil passage 106b that supplies the original pressure of the engagement pressure of the direct clutch C2, and an oil passage that supplies the engagement pressure of the reverse brake B4 106c is connected.

  An oil passage 103 for supplying pilot pressure is connected to the oil passage 102 via a pilot valve PV. The oil passage 103 has an oil passage 103a for supplying pilot pressure to the first solenoid valve SOL1, an oil passage 103b for supplying pilot pressure to the second solenoid valve SOL2, and an oil for supplying pilot pressure to the third solenoid valve SOL3. Passage 103c, an oil passage 103d for supplying pilot pressure to the fourth solenoid valve SOL4, an oil passage 103e for supplying pilot pressure to the fifth solenoid valve SOL5, and an oil passage 103f for supplying pilot pressure to the sixth solenoid valve SOL6 And an oil passage 103g for supplying a pilot pressure to the seventh solenoid valve SOL7.

  FIG. 3 is a schematic diagram illustrating the configuration of the pressure regulating valve according to the first embodiment. The first pressure regulating valve CV1 is connected to the first port a1 connected to the oil passage 105a, the second port a2 connected to the drain circuit, and the oil passage 115a connected to the first switching valve SV1. A third port a3, a fourth port a4 to which the signal pressure of the first solenoid valve SOL1 is supplied, a fifth port a5 to which an oil passage fed back from the oil passage 115a as a counter pressure of this signal pressure is connected, A spring a6 is provided to act against the hydraulic pressure supplied to the four ports.

  In FIG. 3, when the first switching valve SV1 moves upward, the oil passage 105a communicates with the oil passage 115a, while when moved downward, the oil passage 115a communicates with the drain. Similarly, the second pressure regulating valve CV2 to the sixth pressure regulating valve CV6 are provided with the same configuration as the first port a1 to the fifth port a5 and the spring a6, and thus description thereof is omitted.

  FIG. 4 is a schematic diagram illustrating the configuration of the first switching valve SV1 of the first embodiment. The first switching valve SV1 is connected to the first port b1 connected to the oil passage 115a, the second port b2 connected to the drain circuit, the third port b3 connected to the oil passage 115b, and the drain circuit. A fourth port b4, a fifth port b5 connected to an oil passage 150a for supplying hydraulic pressure to the low brake B2, a sixth port b6 connected to an oil passage 150b for supplying hydraulic pressure to the input clutch C1, A seventh port b7 connected to the oil passage 140b that supplies the signal pressure of the seventh solenoid valve SOL7, and a spring b8 that acts opposite to the hydraulic pressure supplied to the seventh port b7 are provided.

  In FIG. 4, when the first switching valve SV1 moves to the left, the oil passage 115a and the oil passage 150a are communicated, and the oil passage 150b and the drain are communicated. On the other hand, when moving to the right, the oil passage 150a and the drain communicate with each other, and the oil passage 115b and the oil passage 150b communicate with each other.

  FIG. 5 is a schematic diagram illustrating the configuration of the second switching valve SV2 of the first embodiment. The second switching valve SV2 includes a first port c1 connected to the oil passage 105d for supplying the D range pressure, a second port c2 connected to the oil passage 106d for supplying the R range pressure, and a sixth pressure regulating valve. The third port c3 connected to the oil passage 120 for supplying hydraulic pressure to the CV6, the fourth port c4 connected to the oil passage 105e for supplying the D range pressure, and the R range pressure as the counter pressure of the fourth port c4. A fifth port c5 connected to the oil passage 106a to be supplied and a spring c6 that acts opposite to the hydraulic pressure supplied to the fourth port c4 are provided.

  In FIG. 5, when the second switching valve SV2 moves to the right, the oil passage 106b communicates with the oil passage 120, while when moved to the left, the oil passage 105d communicates with the oil passage 120.

  FIG. 6 is a schematic diagram illustrating the configuration of the third switching valve SV3 of the first embodiment. The third switching valve SV3 includes a first port d1 connected to an oil passage 122 that supplies hydraulic pressure from the fourth switching valve SV4, and a second port d2 connected to an oil passage 106c that supplies R range pressure. The third port d3 connected to the oil passage 130 for supplying hydraulic pressure to the reverse brake B4, the fourth port d4 connected to the oil passage 140a for supplying the signal pressure of the seventh solenoid valve SOL7, and the fourth port d4 There is provided a spring d5 that opposes the hydraulic pressure supplied to.

  In FIG. 6, when the third switching valve SV3 moves to the right, the oil passage 106c and the oil passage 130 are communicated, and when moved to the left, the oil passage 122 and the oil passage 130 are communicated.

  FIG. 7 is a schematic diagram illustrating the configuration of the fourth switching valve SV4 of the first embodiment. The fourth switching valve SV4 includes a first port e1 connected to an oil passage 121 for supplying hydraulic pressure from the sixth pressure regulating valve CV6, a second port e2 and a third port e3 connected to the drain circuit, and R A fourth port e4 to which the range pressure is supplied, a fifth port e5 to which the D range pressure is supplied, a spring e6 that acts opposite to the fourth port e4, and a seventh port e7 connected to the oil passage 122 And an eighth port e8 connected to the oil passage 123 is provided.

  In FIG. 7, when the fourth switching valve SV4 moves to the right, the oil passage 121 and the oil passage 123 communicate with each other and the oil passage 122 and the drain circuit communicate with each other. On the other hand, when the fourth switching valve SV4 moves to the left, the oil passage 121 and the oil passage The oil passage 123 and the drain circuit are in communication with each other.

  When the clutches C1, C2, C3 and the brakes B1, B2, B3, B4 are in a normal state, as shown in the engagement operation table of FIG. Mark) and release pressure (no mark).

Next, the operation will be described.
[Shifting action]
FIG. 8 is a diagram showing an engagement operation table for the forward 7-speed reverse 1-speed in the automatic transmission gear transmission according to the first embodiment. FIG. 9 is a forward 7-speed reverse 1 in the automatic transmission gear transmission according to the first embodiment. FIG. 10 is a diagram showing an operation table of solenoid valves SOL1 to SOL7 at each gear stage. FIG. 10 is a collinear diagram showing the rotation stop state of members at each gear stage.

<First gear>
In the first speed, different fastening elements act when the engine brake is applied (when the engine brake range position is selected) and when the engine brake is not applied (normally when the forward travel range position is selected). When the engine brake is actuated, it is obtained by engaging the front brake B1, the low brake B2, and the H & LR clutch C3, as shown in FIG. The first one-way clutch F1 provided in parallel with the front brake B1 and the second one-way clutch F2 provided in parallel with the H & LR clutch C3 are also involved in torque transmission. When the engine brake is not applied, the front brake B1 and the H & LR clutch C3 are released, only the low brake B2 is engaged, and torque is transmitted by the first one-way clutch F1 and the second one-way clutch F2.

  In this first speed, since the front brake B1 is engaged (when the engine brake is not operated, the first one-way clutch F1 is engaged), the rotation input from the input shaft Input to the second ring gear R2 is the first planetary gear set GS1. To slow down. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Also, since the low brake B2 and the H & LR clutch C3 are engaged (when the engine brake is not operated, the low brake B2 and the second one-way clutch F2 are engaged), the rotation input to the fourth ring gear R4 is the second planetary gear set. And output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 9, the first speed is the engagement point of the front brake B1 that decelerates the output rotation of the engine and the engagement point of the low brake B2 that decelerates the deceleration rotation from the first planetary gear set GS1. The rotation input from the input shaft Input is decelerated and output from the output shaft Output.

  The torque flow at the first speed is as follows: front brake B1 (or first one-way clutch F1), low brake B2, H & LR clutch C3 (or second one-way clutch F2), first connection member M1, second connection member M2, Torque acts on the three connecting members M3. That is, the first planetary gear set GS1 and the second planetary gear set GS2 are involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, the first to third solenoid valves SOL1 to SOL3 and the sixth and seventh solenoid valves SOL6 and SOL7 are turned on, and the others are turned off. The fastening pressure is supplied to the fastening elements.

  Here, since the seventh solenoid valve SOL7 is on, the first switching valve SV1 moves to the left in FIG. 2, communicates the first pressure regulating valve CV1 and the low brake B2, and connects the input clutch C1 to the drain. (Interlock state prevention). Further, since the D-range pressure is acting on the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 communicate with each other, so the sixth pressure regulating valve. D range pressure acts on CV6. Since the sixth pressure regulating valve CV6 moves downward in FIG. 2, the D range pressure is not supplied to the direct clutch C2 or the fourth switching valve SV4.

  Note that the fourth switching valve SV4 moves to the right in FIG. 2 due to the action of the D range pressure, and is in a state where the oil passage 121 and the oil passage 123 are communicated with each other. Further, since the signal pressure is supplied from the seventh solenoid valve SOL7 to the port d4 to the third switching valve SV3, it moves to the left in FIG. 2, and the first port d1 and the third port d3 are communicated. Since no hydraulic pressure is supplied to the oil passage 122, no hydraulic pressure is supplied to the reverse brake B4.

<Second gear>
In the second speed, different engagement elements are engaged when the engine brake is applied (when the engine brake range position is selected) and when the engine brake is not applied (when the normal forward travel range position is selected). When the engine brake is actuated, it is obtained by engaging the low brake B2, the 2346 brake B3, and the H & LR clutch C3, as shown in FIG. The second one-way clutch F2 provided in parallel with the H & LR clutch C3 is also involved in torque transmission. When the engine brake is not operated, the H & LR clutch C3 is released, the low brake B2 and the 2346 brake B3 are engaged, and torque is transmitted by the second one-way clutch F2.

  In the second speed, since the 2346 brake B3 is engaged, the rotation input from the input shaft Input to the second ring gear R2 is decelerated only by the second planetary gear G2. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Moreover, since the low brake B2 and the H & LR clutch C3 are engaged (when the engine brake is not operated, the second one-way clutch F2 is engaged), the rotation input to the fourth ring gear R4 is decelerated by the second planetary gear set, Output from the third carrier PC3.

  That is, as shown in the collinear diagram of FIG. 9, the second speed is the engagement point of the 2346 brake B3 that decelerates the engine output rotation and the engagement point of the low brake B2 that decelerates the deceleration rotation from the second planetary gear G2. The rotation input from the input shaft Input is decelerated and output from the output gear Output.

  The torque flow in this second speed is caused by the torque acting on the 2346 brake B3, low brake B2, H & LR clutch C3 (or second one-way clutch F2), first connecting member M1, second connecting member M2, and third connecting member M3. To do. That is, the second planetary gear G2 and the second planetary gear set GS2 are involved in torque transmission.

  When upshifting from 1st gear to 2nd gear, release the front brake B1 early and start the engagement of the 2346 brake B3. When the engagement capacity of the 2346 brake B3 is secured, the first one-way clutch F1 is released. Therefore, the accuracy of the shift timing can be improved.

  At this time, as shown in the solenoid valve operation table of FIG. 10, the first, second, fifth to seventh solenoid valves SOL1, SOL2, SOL5, SOL6, SOL7 are turned on, and the others are turned off. A fastening pressure is supplied to the desired fastening element.

  Here, since the seventh solenoid valve SOL7 is turned on, the first switching valve SV1 moves to the left in FIG. 2, the first pressure regulating valve CV1 and the low brake B2 are communicated, and the input clutch C1 is connected to the drain. Connect (prevent interlock state). Further, since the D-range pressure is acting on the fourth port c4 on the second switching valve SV2, it moves to the left in FIG. 2, and the first port c1 and the third port c3 communicate with each other. Since the pressure valve CV6 moves downward in FIG. 2, no hydraulic pressure is supplied to the direct clutch C2 or the third switching valve SV3.

  Further, since the signal pressure is supplied from the seventh solenoid valve SOL7 to the port d4 to the third switching valve SV3, it moves to the left in FIG. 2, and the first port d1 and the third port d3 are communicated. Since no hydraulic pressure is supplied to the oil passage 122, no hydraulic pressure is supplied to the reverse brake B4.

<3rd speed>
As shown in FIG. 8, the third speed is obtained by engaging the 2346 brake B3, the low brake B2, and the direct clutch C2.

  In this third speed, since the 2346 brake B3 is engaged, the rotation input from the input shaft Input to the second ring gear R2 is decelerated by the second planetary gear G2. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the direct clutch C2 is engaged, the fourth planetary gear G4 rotates together. In addition, since the low brake B2 is engaged, the rotation input to the third ring gear R3 via the second connecting member M2 from the fourth carrier PC4 rotating integrally with the fourth ring gear R4 is the third planetary gear G3. And output from the third carrier PC3. As described above, the fourth planetary gear G4 is involved in torque transmission but not in deceleration.

  That is, as shown in the collinear diagram of FIG. 9, the third speed is the engagement point of the 2346 brake B3 that decelerates the engine output rotation and the engagement point of the low brake B2 that decelerates the deceleration rotation from the second planetary gear G2. The rotation input from the input shaft Input is decelerated and output from the output gear Output.

  In the torque flow at the third speed, torque acts on the 2346 brake B3, the low brake B2, the direct clutch C2, the first connecting member M1, the second connecting member M2, and the third connecting member M3. That is, the second planetary gear G2 and the second planetary gear set GS2 are involved in torque transmission.

  When upshifting from 2nd gear to 3rd gear, release the H & LR clutch C3 early and start the engagement of the direct clutch C2, and when the engagement capacity of the direct clutch C2 is secured, the second one-way clutch F2 is released. Therefore, the accuracy of the shift timing can be improved.

  At this time, as shown in the solenoid valve operation table of FIG. 10, turn on the first, second, fourth, fifth and seventh solenoid valves SOL1, SOL2, SOL4, SOL5, SOL7 and turn off the others. Thus, the fastening pressure is supplied to the desired fastening element.

  Here, since the seventh solenoid valve SOL7 is turned on, the first switching valve SV1 moves to the left in FIG. 2, the first pressure regulating valve CV1 and the low brake B2 are communicated, and the input clutch C1 is connected to the drain. Connect (prevent interlock state). Further, since the D range pressure is applied to the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 are communicated. Since the sixth pressure regulating valve CV6 is moving upward in FIG. 2, the regulated hydraulic pressure is supplied to the fourth switching valve SV4.

  Since the D range pressure acts on the fourth switching valve SV4, the oil passage 121 and the oil passage 123 are communicated. Since the oil passage 122 communicates with the drain circuit, the hydraulic pressure is supplied to the direct clutch C2, while the hydraulic pressure is not supplied to the third switching valve SV3. Further, since the signal pressure is supplied from the seventh solenoid valve SOL7 to the port d4 to the third switching valve SV3, it moves to the left in FIG. 2, and the first port d1 and the third port d3 are communicated. Since no hydraulic pressure is supplied to the oil passage 122, no hydraulic pressure is supplied to the reverse brake B4.

<4th speed>
As shown in FIG. 8, the fourth speed is obtained by engaging the 2346 brake B3, the direct clutch C2, and the H & LR clutch C3.

  In the fourth speed, since the 2346 brake B3 is engaged, the rotation input from the input shaft Input to the second ring gear R2 is decelerated only by the second planetary gear G2. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the direct clutch C2 and the H & LR clutch C3 are engaged, the second planetary gear set GS2 rotates integrally. Therefore, the rotation input to the fourth ring gear R4 is output from the third carrier PC3 as it is.

  That is, as shown in the collinear diagram of FIG. 9, the 4th speed is the direct clutch C2 and H & LR that output the reduced rotation from the second planetary gear G2 as it is, the engagement point of the 2346 brake B3 that decelerates the output rotation of the engine. It is defined by a line connecting the engagement point of the clutch C3, and the rotation input from the input shaft Input is decelerated and output from the output gear Output.

  In the torque flow at the fourth speed, torque acts on the 2346 brake B3, the direct clutch C2, the H & LR clutch C3, the first connecting member M1, the second connecting member M2, and the third connecting member M3. That is, the second planetary gear G2 and the second planetary gear set GS2 are involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, by turning on the second and fifth solenoid valves SOL2 and SOL5 and turning off the others, the fastening pressure is supplied to a desired fastening element.

  Here, since the seventh solenoid valve SOL7 is turned off, the first switching valve SV1 moves to the right in FIG. 2, and the low brake B2 communicates with the drain circuit, and the second pressure regulating valve CV2 and the input clutch C1. Is communicated (interlock status prevention). Further, since the D range pressure is applied to the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 are communicated. Since the sixth pressure regulating valve CV6 is moving upward in FIG. 2, the regulated hydraulic pressure is supplied to the fourth switching valve SV4.

  Since the D range pressure acts on the fourth switching valve SV4, the oil passage 121 and the oil passage 123 are communicated. Since the oil passage 122 communicates with the drain circuit, the hydraulic pressure is supplied to the direct clutch C2, while the hydraulic pressure is not supplied to the third switching valve SV3. Further, since the third switching valve SV3 is not supplied with signal pressure from the seventh solenoid valve SOL7 to the port d4, it moves to the right in FIG. 2, and the second port d2 and the third port d3 are communicated. Since the R range pressure is not supplied to the oil passage 106c (is blocked by the manual valve MV), the hydraulic pressure is not supplied to the reverse brake B4.

<5th speed>
The fifth speed is obtained by engaging the input clutch C1, the direct clutch C2, and the H & LR clutch C3 as shown in FIG.

  At the fifth speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second connecting member M2. Further, since the direct clutch C2 and the H & LR clutch C3 are engaged, the third planetary gear G3 rotates integrally. Therefore, the rotation of the input shaft Input is output from the third carrier PC3 as it is.

  That is, as shown in the collinear diagram of FIG. 9, the fifth speed is defined by a line connecting the engagement points of the input clutch C1, the direct clutch C2, and the H & LR clutch C3 that output the output rotation of the engine as it is. The rotation input from Input is output as it is from the output gear Output.

  In the torque flow at the fifth speed, torque acts on the input clutch C1, the direct clutch C2, the H & LR clutch C3, and the second connecting member M2. That is, only the third planetary gear G3 is involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, the fastening pressure is supplied to the desired fastening elements by turning off all the solenoid valves SOL1 to SOL7.

  Here, since the seventh solenoid valve SOL7 is turned off, the first switching valve SV1 moves to the right in FIG. 2, and the low brake B2 communicates with the drain circuit, and the second pressure regulating valve CV2 and the input clutch C1. Is communicated (interlock status prevention). Further, since the D range pressure is applied to the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 are communicated. Since the sixth pressure regulating valve CV6 is moving upward in FIG. 2, the regulated hydraulic pressure is supplied to the fourth switching valve SV4.

  Since the D range pressure is acting on the fourth switching valve SV4, the oil passage 121 and the oil passage 123 are communicated, and the oil passage 122 is communicated with the drain circuit, so that the hydraulic pressure is supplied to the direct clutch C2, On the other hand, the hydraulic pressure is not supplied to the third switching valve SV3. Further, since no signal pressure is supplied to the third switching valve SV3 from the seventh solenoid valve SOL7 to the port d4, the third switching valve SV3 moves to the right in FIG. 2, and the oil passage 106c (second port d2) and the oil passage 130 (second passage). Although the 3 port d3) is in communication, the oil passage 106c is not supplied with the R range pressure (is blocked by the manual valve MV), so that the hydraulic pressure is not supplied to the reverse brake B4.

<6th speed>
As shown in FIG. 8, the sixth speed is obtained by engaging the input clutch C1, the H & LR clutch C3, and the 2346 brake B3.

  In the sixth speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear and also to the second connecting member M2. Further, since the 2346 brake B3 is engaged, the rotation decelerated by the second planetary gear G2 is output from the first connecting member M1 to the fourth ring gear R4. Further, since the H & LR clutch C3 is engaged, the second planetary gear set GS2 outputs the rotation defined by the rotation of the fourth ring gear R4 and the rotation of the second connecting member M4 from the third carrier PC3.

  That is, as shown in the collinear diagram of FIG. 9, the 6th speed is the 2346 brake B3 that decelerates the output rotation of the engine by the second planetary gear G2, and the input clutch that transmits the output rotation of the engine to the second connecting member M2 as it is. C1 is defined by a line connecting the fastening point of the H & LR clutch C3 constituting the second planetary gear set GS2, and the rotation input from the input shaft Input is accelerated and output from the output gear Output.

  In the torque flow at the sixth speed, torque acts on the input clutch C1, the H & LR clutch C3, the 2346 brake B3, the first connecting member M1, the second connecting member M2, and the third connecting member M3. That is, the second planetary gear G2 and the second planetary gear set GS2 are involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, the fifth and sixth solenoid valves SOL5 and SOL6 are turned on, and the other solenoid valves SOL1, SOL2, SOL3, SOL4, and SOL7 are turned off. The fastening pressure is supplied to the fastening elements.

  Here, since the seventh solenoid valve SOL7 is turned off, the first switching valve SV1 moves to the right in FIG. 2, and the low brake B2 communicates with the drain circuit, and the second pressure regulating valve CV2 and the input clutch C1. Is communicated (interlock status prevention). Further, since the D range pressure is applied to the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 are communicated. Since the sixth pressure regulating valve CV6 is moving upward in FIG. 2, the regulated hydraulic pressure is supplied to the fourth switching valve SV4.

  Since the D range pressure is acting on the fourth switching valve SV4, the oil passage 121 and the oil passage 123 are communicated, and the oil passage 122 is communicated with the drain circuit, so that the hydraulic pressure is supplied to the direct clutch C2, On the other hand, the hydraulic pressure is not supplied to the third switching valve SV3. Further, since no signal pressure is supplied to the third switching valve SV3 from the seventh solenoid valve SOL7 to the port d4, the third switching valve SV3 moves to the right in FIG. 2, and the oil passage 106c (second port d2) and the oil passage 130 (second passage). Although the 3 port d3) is in communication, the oil passage 106c is not supplied with the R range pressure (is blocked by the manual valve MV), so that the hydraulic pressure is not supplied to the reverse brake B4.

<7th speed>
As shown in FIG. 8, the seventh speed is obtained by engaging the input clutch C1, the H & LR clutch C3, and the front brake B1 (first one-way clutch F1).

  In the seventh speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear and also to the second connecting member M2. Further, since the front brake B1 is engaged, the rotation decelerated by the first planetary gear set GS1 is output from the first connecting member M1 to the fourth ring gear R4. Further, since the H & LR clutch C3 is engaged, the second planetary gear set GS2 outputs the rotation defined by the rotation of the fourth ring gear R4 and the rotation of the second connecting member M4 from the third carrier PC3.

  That is, as shown in the collinear diagram of FIG. 9, the 7th speed is the front brake B1 that decelerates the engine output rotation by the first planetary gear set GS1, and the input clutch that transmits the engine output rotation to the second connecting member M2 as it is. C1 is defined by a line connecting the fastening point of the H & LR clutch C3 constituting the second planetary gear set GS2, and the rotation input from the input shaft Input is accelerated and output from the output gear Output.

  In the torque flow at the seventh speed, torque acts on the input clutch C1, the H & LR clutch C3, the front brake B1, the first connecting member M1, the second connecting member M2, and the third connecting member M3. That is, the first planetary gear set GS1 and the second planetary gear set GS2 are involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, the third and sixth solenoid valves SOL3 and SOL6 are turned on, and the other solenoid valves SOL1, SOL2, SOL4, SOL5, and SOL7 are turned off. The fastening pressure is supplied to the fastening elements.

  Here, since the seventh solenoid valve SOL7 is turned off, the first switching valve SV1 moves to the right in FIG. 2, and the low brake B2 communicates with the drain circuit, and the second pressure regulating valve CV2 and the input clutch C1. Is communicated (interlock status prevention). Further, since the D range pressure is applied to the fourth port c4, the second switching valve SV2 moves to the left in FIG. 2, and the first port c1 and the third port c3 are communicated. Since the sixth pressure regulating valve CV6 is moving upward in FIG. 2, the regulated hydraulic pressure is supplied to the fourth switching valve SV4.

  Since the D range pressure is acting on the fourth switching valve SV4, the oil passage 121 and the oil passage 123 are communicated, and the oil passage 122 is communicated with the drain circuit, so that the hydraulic pressure is supplied to the direct clutch C2, On the other hand, the hydraulic pressure is not supplied to the third switching valve SV3. Further, since no signal pressure is supplied to the third switching valve SV3 from the seventh solenoid valve SOL7 to the port d4, the third switching valve SV3 moves to the right in FIG. 2, and the oil passage 106c (second port d2) and the oil passage 130 (second passage). Although the 3 port d3) is in communication, the oil passage 106c is not supplied with the R range pressure (is blocked by the manual valve MV), so that the hydraulic pressure is not supplied to the reverse brake B4.

<Reverse speed>
As shown in FIG. 8, the reverse speed is obtained by engaging the H & LR clutch C3, the front brake B1, and the reverse brake B4.

  At this reverse speed, since the front brake B1 is engaged, the rotation decelerated by the first planetary gear set GS1 is output from the first connecting member M1 to the fourth ring gear R4. Further, since the H & LR clutch C3 is engaged and the reverse brake B4 is engaged, the second planetary gear set GS2 performs the rotation defined by the rotation of the fourth ring gear R4 and the fixation of the second connecting member M2 to the third carrier. Output from PC3.

  That is, as shown in the collinear diagram of FIG. 9, the reverse speed includes the front brake B1 that decelerates the output rotation of the engine by the first planetary gear set GS1, the reverse brake B4 that fixes the rotation of the second connecting member M2, and the second Specified by a line connecting the fastening point of the H & LR clutch C3 constituting the planetary gear set GS2, the rotation input from the input shaft Input is decelerated in the reverse direction and output from the output gear Output.

  In the torque flow at the reverse speed, torque acts on the H & LR clutch C3, the front brake B1, the reverse brake B4, the first connecting member M1, the second connecting member M2, and the third connecting member M3. That is, the first planetary gear set GS1 and the second planetary gear set GS2 are involved in torque transmission.

  At this time, as shown in the solenoid valve operation table of FIG. 10, turn on the second, third and sixth solenoid valves SOL2, SOL3, SOL6 and turn off the other solenoid valves SOL1, SOL4, SOL5, SOL7. Thus, the fastening pressure is supplied to the desired fastening element. The seventh solenoid SOL7 is turned on at the initial stage of R range switching and turned off after completion of the fastening.

  The R range pressure is supplied to the reverse brake B4 via the third switching valve SV3. Since the R range does not have a dedicated pressure regulating valve, the fastening pressure of the reverse brake B4 is regulated using the sixth pressure regulating valve CV6 used for the direct clutch C2 in the initial stage of engagement. First, when the manual valve MV switches to the R range pressure, the second switching valve SV2 moves to the right in FIG. 2, and the R range pressure is supplied to the sixth pressure regulating valve CV6. Further, the fourth switching valve SV4 moves to the left in FIG. 2 and communicates the oil passage 121 and the oil passage 122. As a result, the hydraulic pressure regulated by the sixth pressure regulating valve CV6 is introduced into the oil passage 122.

  When the seventh solenoid valve SOL7 is turned on in this state, the third switching valve SV3 moves to the left in FIG. 2 and connects the oil passage 122 and the oil passage 130. Therefore, while the seventh solenoid valve SOL7 is on, the engagement pressure of the reverse brake B4 is controlled by the hydraulic pressure regulated by the sixth pressure regulating valve CV6. When the fastening is completed, the seventh solenoid valve SOL7 is turned off. Then, the third switching valve SV3 moves to the right in FIG. 2, and the oil passage 106c and the oil passage 130 are communicated with each other, so that the R range pressure is introduced as it is and the engaged state is maintained.

  Thus, by providing the third switching valve SV3 and the fourth switching valve SV4, it is possible to control the fastening pressures of the two fastening elements with one pressure regulating valve.

(Regarding the action of the first switching valve)
Next, the operation of the first switching valve SV1 will be described based on the above operation. The first switching valve SV1 is a switching valve provided to ensure that the low brake B2 and the input clutch C1 are not simultaneously engaged. For example, even if the first solenoid valve SOL1 and the second solenoid valve SOL2 fail and generate a fastening pressure at the same time, if the first switching valve SV1 is not biased to either one, it is fastened to the fastening element. No pressure is supplied. Therefore, the interlock state is surely prevented.

  In addition, as shown in the engagement table of FIG. 8 and the solenoid operation table of FIG. 10, the low brake B2 and the input clutch C1 are engaged with the low brake B2 from the 1st to 3rd speeds, and the low brake B2 is engaged otherwise. Never do. On the other hand, from the fifth speed to the seventh speed, the input clutch C1 is engaged, and otherwise the input clutch C1 is not engaged. This means that neither the low brake B2 nor the input clutch C1 is engaged in the fourth speed.

  When an interlock state prevention valve such as the first switching valve SV1 is configured, the low brake B2 is engaged and the input clutch C1 is disengaged at a certain gear position. When B2 is released and the input clutch C1 is engaged, the release pressure control for the low brake B2 and the engagement pressure control for the input clutch C1 are performed during the switching control. Then, it is very difficult to specify the best timing for switching the first switching valve SV1. In addition, it is impossible to control such that both the fastening elements have the fastening capacity at the same time to advance the inertia phase.

  On the other hand, when the first switching valve SV1 is switched, there is a gear stage that does not involve both fastening elements, that is, the fourth speed, and turning off the seventh solenoid valve SOL7 during the fourth speed traveling affects the speed change control. The interlock state is surely prevented without any problems.

(About control processing at the time of failure)
Here, in the failure of the automatic transmission, the failure to be monitored usually includes an interlock state failure, a neutral state failure, and an abnormal gear ratio failure.

  The interlock state failure is a failure in which the rotation of the input shaft Input and the rotation of the output shaft Output are simultaneously fixed by the fastening failure of some fastening elements. Therefore, when an interlock state failure occurs, a force for rapidly fixing the drive wheels acts during traveling, and can be detected by monitoring vehicle body deceleration or the like.

  The neutral state failure is a failure in which the rotation of the input shaft Input must be fastened at the command shift stage, and the engagement element is not transmitted to the output shaft Output due to a release failure. Therefore, when a neutral state failure occurs, the rotational speed of the output shaft Output with respect to the rotational speed of the input shaft Input becomes very small during traveling, and the actual gear ratio (= input rotation / output rotation) depends on the command gear stage. It can be detected by monitoring that the gear ratio becomes abnormally larger than the gear ratio.

  An abnormal gear ratio failure means that the actual gear ratio that represents the input / output ratio of the input shaft Input and the output shaft Output is a slight slip of the fastening element that must be fastened at the command gear stage, or is fastened at the command gear stage. This is a failure that deviates by more than a predetermined value from the gear ratio corresponding to the command shift stage due to a fastening failure or a release failure of a fastening element that is not allowed.

  Note that the “engagement failure” in the first embodiment represents a failure that remains in the engaged state despite the output of the release command, in other words, a failure that is not completely released, and is referred to as “release failure”. Represents a failure that remains released despite the output of a fastening command, in other words, a failure that does not result in complete fastening. In addition, a failure caused by an electrical failure such as a disconnection or a short circuit of a solenoid or the like can be detected by measuring a current value or the like. For example, a state where a valve is caught by the influence of contamination or the like in the hydraulic circuit, that is, a failure caused by a so-called valve stick or the like is assumed. This is because a valve stick or the like cannot be detected other than logically estimated from a phenomenon actually occurring in the automatic transmission.

  Therefore, an interlock state failure, a neutral state failure, and a gear ratio abnormality failure are specified, and when the interlock state failure occurs, the shift to the avoiding gear stage is specified, and the abnormal point is specified, and the shift control that can secure the driving force is performed. We decided to carry out. Note that the avoidance shift stage refers to a shift stage achieved by control performed by detecting a failure, and not only a temporary shift stage from the failure detection to the vehicle stop but also a shift stage after restarting. Is also included. Hereinafter, this failure detection process will be described.

  FIG. 11 is a flowchart showing the failure detection process. It is assumed that this process is executed at every control cycle set in advance in the ATCU 20.

  In step S1, an abnormality detection control process is executed. The abnormality detection control process refers to control for determining whether an abnormality occurring in the automatic transmission is caused by an interlock state failure, a gear ratio abnormality failure, or a neutral state failure. Details will be described later.

  In step S2, when it is determined by the abnormality detection control process that there is an abnormality, the process proceeds to step S3. Otherwise, the process returns to step S1 and the abnormality detection control process is repeated.

  In step S3, avoidance shift speed control is executed. The avoidance shift stage control means that it is possible to maintain the driving force while avoiding an abnormal state in view of the fact that traveling with a sufficient driving force cannot be maintained at the command shift stage in which an abnormality is detected or there is a risk of impairing safety. Control that temporarily shifts to a different gear. Details will be described later.

  In step S4, it is determined whether or not the vehicle has stopped. If the vehicle has stopped, the process proceeds to step S5. Otherwise, step S3 is repeated. In other words, the state where the avoidance shift stage achieved by the avoidance shift control is maintained until the vehicle stops.

  In step S5, a search control process is executed when the vehicle restarts after the vehicle stops. Probing control refers to control for outputting a specific command shift stage in order to specify an abnormal part detected by the abnormality detection control process. When the above-described abnormality occurs and the avoidance shift speed control is executed, the failure site cannot be specified if sufficient time can be secured. However, if a failure occurs during a sudden stop, etc., it is possible that the vehicle will stop before the failure site is specified, and it is difficult to specify the actual gear ratio etc. when the vehicle is stopped. The failure part is determined at the time of restart. Details will be described later.

  In step S6, an abnormal time shift control process is executed. The abnormal speed change control process is based on the failure location specified in each of the above steps, using only normal fastening elements, or if there is a fastening failure, using the fastening to some degree This is a control that secures traveling performance by this shift speed. Details will be described later.

[Abnormality detection control processing]
Next, the abnormality detection control process executed in step S1 will be described. FIG. 12 is a flowchart showing the abnormality detection control process.

  In step 101, it is determined whether the inhibitor switch signal is in the normal forward travel range or the engine brake range. If the inhibitor switch signal is in the normal forward travel range or the engine brake range, the process proceeds to step 102. Otherwise, the control flow ends.

  In step 102, it is determined whether the foot brake is in a non-operating state (for example, foot brake OFF) and the vehicle acceleration G is less than the set value. If less than the set value, the process proceeds to step 103; Advances to step 106. In other words, when an interlock state failure occurs, it is detected that the acceleration G of the vehicle rapidly decreases.

  In step 103, the timer t is counted up.

  In Step 104, it is determined whether or not the count value of the timer t is larger than the set value. If it is larger, the process proceeds to Step 107. Otherwise, the process returns to Step 102, and Step 102 and the subsequent steps are repeated. When the count value of the timer t is larger than the set value, it is determined that a failure has occurred because the condition that satisfies the above condition continuously occurs. On the other hand, the case where the condition is temporarily satisfied due to the influence of noise or the like is excluded.

  In step 105, it is determined that an interlock state failure has occurred.

  In step 106, the timer t is reset to zero.

  In step 107, it is determined whether or not the actual gear ratio exists in the gear ratio abnormality determination region. If it exists, the process proceeds to step 108. Otherwise, the process proceeds to step 111. Note that the gear ratio abnormality determination region represents a region where the actual gear ratio becomes large with respect to the gear ratio corresponding to the command gear as shown in FIG. FIG. 17 is a diagram illustrating a relationship between a command shift speed and a shift speed that can be achieved when a failure occurs in the command shift speed. In FIG. 17, the actual gear ratio according to the command shift speed is indicated by ○, and the actual gear ratio that can be achieved by the engagement failure or release failure of one engagement element at the command shift speed is indicated by ☆. . In FIG. 17, the shaded area represents a neutral state failure.

  In step 108, the timer t is counted up.

  In Step 109, it is determined whether or not the count value of the timer t is larger than the set value. If it is larger, the process proceeds to Step 110. Otherwise, the process returns to Step 107, and Step 107 and the subsequent steps are repeated. Since this operation is the same as that in step 104, description thereof is omitted.

  In step 110, it is determined that the gear ratio is abnormal.

  In step 111, the timer t is reset to zero.

  In step 112, it is determined whether or not the actual gear ratio is in a region representing a neutral state failure. If the actual gear ratio is in that region, the process proceeds to step 113. Otherwise, the process returns to step 102, and step 102 and subsequent steps are repeated. As shown in FIG. 17, the region representing the neutral state failure is a region that is larger than the gear ratio of the gear that is about one step smaller than the gear ratio corresponding to the commanded gear, and is represented by the hatched region in the figure. .

  In step 113, the timer t is counted up.

  In step 114, it is determined whether or not the count value of the timer t is larger than the set value. If it is larger, the process proceeds to step 110. Otherwise, the process returns to step 107, and step 107 and subsequent steps are repeated. Since this operation is the same as that in step 104, description thereof is omitted.

  In step 115, it is determined that a neutral state failure has occurred.

  By the abnormality detection control process, an interlock state failure, a gear ratio abnormality failure, and a neutral state failure can be detected.

[Interlocking gear failure avoidance gear position control process]
Next, an avoidance shift speed control flow when it is determined by the above control flow that the interlock state has failed will be described. FIG. 13 is a flowchart showing an avoidance shift stage control process when it is determined that the interlock state is faulty.

[First-speed, second-speed, and third-speed avoidance shift stage control processing]
In step 201, it is determined whether the command gear position at the time of detecting the interlock state is any one of the first speed, the second speed, and the third speed. If the first speed, the second speed, and the third speed, the process proceeds to step 202. If so, go to Step 206.

  In step 202, all fastening elements are released.

  In step 203, it is determined whether or not the vehicle speed is less than a set value representing a low vehicle speed. If the vehicle speed is less than the set value, the process proceeds to step 204. Otherwise, this step is repeated.

  In step 204, the low brake B2 is engaged.

  In step 205, a shift is made to the avoidance gear.

[Fastening failure location identification processing]
In step 2051, the actual gear ratio is detected.

  In Step 2052, it is determined whether or not the actual gear ratio is the second speed. If the actual gear ratio is the second speed, the process proceeds to Step 2053. Otherwise, the process proceeds to Step 2054.

  In Step 2053, the 2346 brake B3 is identified as an engagement failure.

  In Step 2054, it is determined whether or not the actual gear ratio is 1.5 speed. If it is 1.5 speed, the process proceeds to Step 2055. Otherwise, the process proceeds to Step 2056.

  In step 2055, the direct clutch C2 is identified as an engagement failure.

  In step 2056, it is determined whether or not the engine brake is applied. When the engine brake is applied, the process proceeds to step 2057. Otherwise, the process proceeds to step 2058.

  In step 2057, the H & LR clutch C3 is identified as an engagement failure.

  In step 2058, the front brake B1 is identified as an engagement failure.

[4th speed avoidance gear position control process]
In step 206, it is determined whether or not the command gear position at the time of detection of the interlock state is the fourth speed. If it is the fourth speed, the process proceeds to step 207. Otherwise, the process proceeds to step 208.

  In step 207, the 2346 brake B3 is released.

[Fastening failure location identification processing]
In step 2071, the actual gear ratio is detected.

  In Step 2072, it is determined whether or not the actual gear ratio is the fifth speed. If the actual gear ratio is the fifth speed, the process proceeds to Step 2074. Otherwise, the process proceeds to Step 2073.

  In Step 2073, the front brake B1 is identified as an engagement failure.

  In step 2074, the input clutch C1 is identified as an engagement failure.

[5th speed avoidance gear position control process]
In step 208, it is determined whether or not the command shift speed at the time of detection of the interlock state is the fifth speed. If it is the fifth speed, the process proceeds to step 209. Otherwise, the process proceeds to step 210.

  In step 209, the direct clutch C2 is released.

[Fastening failure location identification processing]
In step 2091, the actual gear ratio is detected.

  In Step 2092, it is determined whether or not the actual gear ratio is 6th speed. If 6th speed, the process proceeds to Step 2094. Otherwise, the process proceeds to Step 2093.

  In Step 2093, the front brake B1 is identified as an engagement failure.

  In Step 2094, the 2346 brake B3 is identified as an engagement failure.

[6th speed avoidance gear position control process]
In step 210, it is determined whether or not the command shift speed at the time of detection of the interlock state is the sixth speed. If it is the sixth speed, the process proceeds to step 211. Otherwise, the process proceeds to step 212.

  In step 211, the 2346 brake B3 is released.

[Fastening failure location identification processing]
In step 2111, the actual gear ratio is detected.

  In step 2112, it is determined whether or not the actual gear ratio is the fifth speed. If the actual gear ratio is the fifth speed, the process proceeds to step 2114. Otherwise, the process proceeds to step 2113.

  In step 2113, the front brake B1 is identified as an engagement failure.

  In step 2114, the direct clutch C2 is identified as an engagement failure.

[7-speed avoidance gear position control process]
In step 212, it is determined that the command gear position at the time of detecting the interlock state is the seventh speed, and the front brake B1 is released.

[Fastening failure location identification processing]
In step 2121, the actual gear ratio is detected.

  In step 2122, it is determined whether the actual gear ratio is 6th speed. If 6th speed, the process proceeds to step 2124. Otherwise, the process proceeds to step 2123.

  In step 2123, the direct clutch C2 is identified as an engagement failure.

  In step 2124, the 2346 brake B3 is identified as an engagement failure.

  Next, the operation of the avoidance shift speed control process will be described. In the automatic transmission according to the first embodiment, when the four fastening elements are fastened simultaneously, the interlock state is established. In other words, when three normal fastening elements are fastened and one of the other fastening elements is fastened and the interlocking state is generated by one fastening failure, the three fastening elements to be fastened to achieve the command shift speed are considered. Any of the fastening elements can operate normally. Therefore, if any one of the three normal fastening elements that achieve this command shift speed is released, the driving force can be secured while avoiding the interlock state. Hereinafter, description will be made along this logic. The avoidance shift stage is used to mean a shiftable stage that can be achieved for avoiding a failure after detecting a failure such as an interlock state.

  In addition, the input clutch C1 is in the 1st, 2nd, and 3rd speeds, the oil passage is mechanically shut off by the first switching valve SV1, and there is no failure in engagement. The failure of the input clutch C1 is eliminated. Similarly, the reverse brake B4 is also mechanically shut off by the fourth switching valve SV4 and does not cause an engagement failure. Therefore, the engagement failure of the reverse brake B4 is eliminated.

(I) When the gear position is 1st, 2nd, or 3rd when the interlock state is detected The interlock state occurs at the 1st, 2nd or 3rd speed because of an H & LR clutch C3 engagement failure or front brake B1. Caused by the failure of the 2346 brake, the failure of the 2346 brake, and the failure of the direct clutch C2. At this time, by disengaging all but the low brake B2, it is possible to ensure the avoidance shift stage by two of the fastening elements that have failed to engage with the low brake B2.

  Specifically, because the low brake B2 is always engaged in the 1st, 2nd, and 3rd speeds, if a failure occurs in any of the engagement elements, only the low brake B2 is maintained and other engagements are made. By releasing the element, one of the first, 1.5th, and second gears can be achieved. Note that the 1.5th speed is a shift stage achieved by engaging the first one-way clutch F1, the direct clutch C2, and the low brake B2, as shown in the collinear diagram of FIG.

  FIG. 14 is a diagram showing the correlation between the shift speeds achieved in the relationship between the engagement failure element for the command shift speed and the released engagement element. As shown in FIG. 14, the second speed without engine braking is achieved by fastening the 2346 brake B3 and the low brake B2. In addition, the 1st speed of the engine braking action is achieved by engaging the H & LR clutch C3 and the low brake B2. The 1.5-speed engine braking action is achieved by engaging the direct clutch C2 and the low brake B2. Also, the first speed with no engine brake is achieved by fastening the front brake B1 and the low brake B2.

  Here, in the case of a multi-stage transmission, the first gear and the second gear (corresponding to the predetermined gear stage described in the claims) have recently become large gears due to the widening of the gear ratio considering fuel consumption and the like. The ratio is set. The interstage ratio is also set larger on the low speed side than on the high speed side. For this reason, if the gear is suddenly shifted to the 1st speed or the 2nd speed to avoid the interlock state, even if the failure is detected at the 3rd speed, a very large engine brake is applied and the vehicle speed is high. It is also conceivable that a deceleration similar to that occurring in the locked state is generated.

  Also in the present embodiment, when all the normal engagement elements are released while the low brake B2 is engaged, a significant downshift is accompanied, and the engine brake may act depending on the engagement element that has failed. Therefore, when the vehicle speed Vsp is higher than the set value that may cause an abrupt engine braking action, a release command is output to all engagement elements, and the low brake B2 is engaged after the vehicle speed Vsp becomes less than the set value. As a result, the driving force was secured without causing a sudden engine braking action or the like.

  When the actual gear ratio is detected after the low brake B2 is engaged, the gear ratio of any one of the first speed, the 1.5th speed, and the second speed should be achieved as shown in FIG. Therefore, the fault location can be identified by detecting the actual gear ratio and determining which gear stage the actual gear ratio has a correlation with. Note that the front brake B1 and the H & LR clutch C3 cannot be specified unless it is detected whether the engine brake is generated. Specifically, it may be detected from a change in engine speed when the accelerator is off.

(Ii) When the command shift stage at the time of interlock state detection is the fourth speed The interlock state occurs at the fourth speed due to the engagement failure of the input clutch C1 and the engagement failure of the front brake B1. In the fourth speed, the 2346 brake B3 is to be released from the normal three engagement elements, regardless of whether the input clutch C1 or the front brake B1 is engaged. As a result, a shift speed higher than the second speed can be achieved as an avoidance shift speed, and an avoidance shift speed without a significant downshift can be achieved. Specifically, 5th speed is achieved by releasing the 2346 brake B3 when the input clutch C1 is broken, and 2.5 speed is achieved by releasing the 2346 brake B3 when the front brake B1 is broken. Achieve. Note that the 2.5 speed is a shift stage achieved by engaging the front brake B1 (first one-way clutch F1), the direct clutch C2, and the H & LR clutch C3, as shown in the collinear diagram of FIG.

  When the actual gear ratio is detected after the release of the 2346 brake B3, either the fifth gear ratio or the 2.5th gear ratio should be achieved as shown in FIG. Therefore, the fault location can be identified by detecting the actual gear ratio and determining which gear stage the actual gear ratio has a correlation with.

(Iii) When the interlocking speed is detected and the command gear is 5th. The interlocking state occurs at the 5th speed due to the engagement failure of the 2346 brake B3 and the engagement failure of the front brake B1. At the fifth speed, the direct clutch C2 is released from the normal three engagement elements, regardless of whether the 2346 brake B3 or the front brake B1 is engaged. As a result, a shift speed higher than the second speed can be achieved as an avoidance shift speed, and an avoidance shift speed without a significant downshift can be achieved. Specifically, 6-speed is achieved by releasing the direct clutch C2 when the 2346 brake B3 engagement failure occurs, and 2.5-speed is achieved by releasing the direct clutch C2 when the front brake B1 engagement failure occurs. To do.

  When the actual gear ratio is detected after the direct clutch C2 is released, the gear ratio of either 6th speed or 7th speed should be achieved as shown in FIG. Therefore, the fault location can be identified by detecting the actual gear ratio and determining which gear stage the actual gear ratio has a correlation with.

(Iv) When the gear shift position is 6th when the interlock state is detected The interlock state occurs at the 6th speed due to the engagement failure of the direct clutch C2 or the engagement failure of the front brake B1. In 6th gear, the 2346 brake B3 is released from the normal 3 engagement elements, regardless of whether the direct clutch C2 or the front brake B1 is engaged. As a result, a shift speed higher than the second speed can be achieved as an avoidance shift speed, and an avoidance shift speed without a significant downshift can be achieved. Specifically, the fifth speed is achieved by releasing the 2346 brake B3 when the direct clutch C2 engagement failure occurs, and the seventh speed is achieved by releasing the 2346 brake B3 when the front brake B1 engagement failure occurs. Therefore, when the interlocking state detection command shift speed is 6th speed, the avoidance shift speed is achieved by releasing the 2346 brake B3.

  When the actual gear ratio is detected after the release of the 2346 brake B3, the gear ratio of either the fifth speed or the seventh speed should be achieved as shown in FIG. Therefore, the fault location can be identified by detecting the actual gear ratio and determining which gear stage the actual gear ratio has a correlation with.

(V) When the interlock speed is detected when the command gear is in the 7th speed The interlock condition occurs in the 7th speed due to the engagement failure of the 2346 brake B3 and the engagement failure of the direct clutch C2. At 7th speed, the front brake B1 is released from the normal three engagement elements, regardless of whether the 2346 brake B3 or the direct clutch C2 is engaged. As a result, a shift speed higher than the second speed can be achieved as an avoidance shift speed, and an avoidance shift speed without a significant downshift can be achieved. Specifically, the 6th speed is achieved by releasing the front brake B1 when the engagement failure of the 2346 brake B3 occurs, and the 5th speed is achieved by releasing the front brake B1 when the engagement failure of the direct clutch C2 occurs. . Therefore, when the interlock state detection command shift speed is 7th speed, the avoidance shift speed is achieved by releasing the front brake B1.

  If the actual gear ratio is detected after the front brake B1 is released, either the fifth gear or the sixth gear should be achieved as shown in FIG. Therefore, the fault location can be identified by detecting the actual gear ratio and determining which gear stage the actual gear ratio has a correlation with.

  As described in (i) to (v) above, when the instructed gear is 1st, 2nd, or 3rd when a failure is detected, the gear on the higher speed side than the 2nd is reliably achieved. Because it is not possible, after outputting the release command to all the engagement elements once, waiting for the vehicle speed to drop and engaging the low brake B2 to achieve the avoidance shift stage, the instruction shift stage when the failure is detected is 4th speed, In the fifth speed, the sixth speed, and the seventh speed, one of the fastening elements that achieve the indicated shift speed is released to achieve an avoidance shift speed that is higher than the second speed. The reason why such separation is possible is that the first switching valve SV1 mechanically eliminates simultaneous engagement of the low brake B2 and the input clutch C1.

  The low brake B2 is engaged only at the 1st, 2nd and 3rd speeds, and the input clutch C1 is engaged only at the 5th to 7th speeds. If the possibility of a low brake B2 engagement failure cannot be ruled out at the 4th, 5th, 6th, and 7th speeds, if a low brake B2 engagement failure occurs, even if one engagement element is released, There is a risk of achieving a shift stage with a downshift. On the other hand, in the first embodiment, in the fourth speed, the fifth speed, the sixth speed, and the seventh speed, the possibility of the engagement failure of the low brake B2 is eliminated by the first switching valve SV1, and only one engagement element is released. Thus, the shift speed higher than the predetermined shift speed can be achieved as the avoidance shift speed, and no significant downshift occurs.

  Also, once all the fastening elements are released, the low brake B2 is engaged only when the vehicle speed Vsp becomes less than the set value, so a sudden braking force is applied to the drive wheels due to the action of the engine brake. Occurrence can be prevented.

  In addition, when an interlock state occurs, a plurality of fastening elements are not operated, and only one fastening element of the indicated gear speed when a failure is detected is operated. There is still a possibility that other avoiding shift speeds can be achieved by controlling the engagement / release of multiple engagement elements, but depending on the engagement / release timing, a significant reduction can be achieved via a shift stage with a significant downshift. This is not preferable because there is a possibility of reaching a gear position without downshifting. In addition, it is possible to avoid the gear shift stage by releasing only one fastening element because it is under a sudden deceleration of the interlock state and it is desired to avoid it as soon as possible, and complicated control is difficult in the failure state. As a result, the effect of improving the robustness of the avoidance shift stage control process can be obtained.

  On the 1st, 2nd and 3rd speeds, after the low brake B2 is engaged, on the 4th, 5th, 6th and 7th speeds, based on the actual gear ratio after one normal engagement element is released. It is possible to identify a fastening element that has failed in engagement. For example, immediately after the vehicle stops, it is possible to appropriately achieve speed change control within a shift speed that uses the engagement element that has failed. Thereby, even if the interlock state failure occurs, it is possible to improve the traveling performance by securing the driving force.

[Avoiding gear stage control process in case of gear ratio abnormality failure]
Next, the avoidance shift stage control process when a gear ratio abnormality failure is detected will be described. In the gear ratio abnormality, the actual gear ratio deviates from the gear ratio corresponding to the command shift stage due to slight slipping of the fastening element, and the input shaft is interlocked due to the fastening failure of the fastening element, and the output shaft is in the neutral state. Since there are cases where the actual gear ratio shifts due to this, they will be described separately.

(About the input shaft interlock state and the output shaft neutral state)
Next, the case where the input shaft is in the interlock state and the output shaft is in the neutral state in the first embodiment will be described. FIG. 15 is a diagram illustrating a change in the nomograph when the engagement failure occurs in the 2346 brake B3 during the first speed traveling while the engine brake range position is selected.

  In FIG. 15, the rigid lever representing the first planetary gear set GS1 is L1, the rigid lever representing the second planetary gear set GS2 is L2, the rigid lever of the third planetary gear G3 is L23, and the fourth planetary gear G4 Define the rigid lever as L24. Here, the rigid lever is a linear representation of the rotational speed ratio of each rotating element (sun gear, carrier, ring gear) of the planetary gear, and the torque input / output can be expressed simultaneously. In FIG. 15, thick arrows indicate torque input / output directions. A solid line indicates a normal time, and a thick dotted line indicates a failure.

  When driving at the first speed while the engine brake range position is selected, the front brake B1 is engaged, the H & LR clutch C3 is engaged, and the low brake B2 is engaged. At this time, when an upward torque in FIG. 15 acts on the input shaft Input, an upward torque acts on the front brake B1, and a downward torque acts on the first ring gear R1 and the second carrier PC2. The downward torque output from the first planetary gear set GS1 is input as the upward torque to the fourth ring gear R4 of the second planetary gear set GS2. In the second planetary gear set GS2, upward torque acts on the low brake B2, and downward torque is output from the output shaft Output.

  In this state, when an engagement failure occurs in the 2346 brake B3, a force that raises the rotational speeds of the first and second sun gears S1 and S2 to 0 acts on the rigid lever L1. However, since the front brake B1 is engaged, it rotates around this engagement point, and the rotational speeds of all the rotating elements of the first planetary gear set GS1 are reduced to 0 (input shaft interlock state).

  Then, the rotation speed of the fourth ring gear R4 of the second planetary gear set GS2 connected via the first connecting member M1 is also reduced. At this time, since the fourth planetary gear G4 is only connected to the third sun gear S3 fixed to the low brake B2 via the second one-way clutch F2, the rigid lever is centered on the fourth carrier PC4. L24 will rotate.

  On the other hand, the third planetary gear G3 constituting the second planetary gear set GS2 has its rotational speed regulated by the low brake B2 and the output shaft Output, but from the fourth carrier PC4 of the fourth planetary gear G4 to the third ring gear R3. The reaction force of can not be obtained, it will be in a neutral state.

  Therefore, even if the driver depresses the accelerator pedal, the engine speed is unlikely to increase due to the input shaft interlock state. On the other hand, the vehicle speed (output shaft rotation) differs from the normal interlock state, and there is no sudden deceleration and inertia. It becomes a running state.

  FIG. 16 is a diagram illustrating a change in the nomograph when a fastening failure occurs in the front brake B1 during the second speed traveling.

  During 2nd speed, 2346 brake B3 is engaged, H & LR clutch C3 is engaged, and low brake B2 is engaged. At this time, when an upward torque in FIG. 16 acts on the input shaft Input, an upward torque acts on the 2346 brake B3, and a downward torque acts on the first ring gear R1 and the second carrier PC2. The downward torque output from the first planetary gear set GS1 is input as the upward torque to the fourth ring gear R4 of the second planetary gear set GS2. In the second planetary gear set GS2, upward torque acts on the low brake B2, and downward torque is output from the output shaft Output.

  In this state, when a fastening failure occurs in the front brake B1, a force that lowers the rotational speed of the first carrier PC1 to 0 acts on the rigid lever L1. However, since the 2346 brake B3 is engaged, it rotates around this engagement point, and the rotational speeds of all the rotating elements of the first planetary gear set GS1 are reduced to 0 (input shaft interlock state).

  Then, the rotation speed of the fourth ring gear R4 of the second planetary gear set GS2 connected via the first connecting member M1 is also reduced. At this time, the fourth planetary gear G4 is only connected to the third sun gear S3 fixed to the low brake B2 via the second one-way clutch F2, and the rigid lever L24 is centered on the fourth carrier PC4. Will rotate.

  On the other hand, the third planetary gear G3 constituting the second planetary gear set GS2 has its rotational speed regulated by the low brake B2 and the output shaft Output, but from the fourth carrier PC4 of the fourth planetary gear G4 to the third ring gear R3. The reaction force cannot be obtained and the neutral state is established (output shaft neutral).

  Therefore, even if the driver depresses the accelerator pedal, the engine speed is unlikely to increase due to the input shaft interlock state. On the other hand, the vehicle speed (output shaft rotation) differs from the normal interlock state, and there is no sudden deceleration and inertia. It becomes a running state.

  As described above, in the case of the automatic transmission of the first embodiment, the front brake is applied when the engagement failure occurs in the 2346 brake B3 during the first speed traveling while the engine brake range position is selected, and during the second speed traveling regardless of the range position. There are cases where the input shaft interlock state and the output shaft neutral state occur when a fastening failure occurs in B1. For this reason, the detection itself is difficult with the conventional technique in which an abnormality is determined when the gear ratio increases. Incidentally, when the input shaft is interlocked and the output shaft is in the neutral state, the actual gear ratio is small.

  Also, when a failure is determined from the difference between the current gear and the actual gear ratio, it can be determined that some failure has occurred, but it is not considered to specify what kind of failure, so all failures are not considered. In view of this, fail-safe control must be performed to ensure safety in all of these failures, and as a result, the gears that can be selected at the time of failure are limited, and the running performance is greatly deteriorated at the time of failure. There is.

  Further, in order to determine the failure as described above, it may be possible to provide a hydraulic switch for detecting whether or not the hydraulic pressure is supplied to the hydraulic circuit of each friction element, but the layout of the oil path becomes complicated, Problems such as an increase in the size of the valve and an increase in the number of parts are inevitable.

  In the automatic transmission according to the first embodiment, the state where both the low brake B2 and the input clutch C1 are simultaneously engaged by the first switching valve SV1 is mechanically excluded. Therefore, the low brake B2 and the input clutch C1 are always Write on the premise that they will not be concluded at the same time.

  In the case of a shift stage that can be achieved when a fastening failure or a release failure of any fastening element occurs in the command shift stage, a neutral state failure does not occur due to slipping of the fastening element. Therefore, as shown in FIG. 17, the actual gear ratio region realized only by the slip of the fastening element is set to the neutral state failure region indicated by hatching for each command shift stage. In the automatic transmission according to the first embodiment, at the sixth speed and the seventh speed, other gear speeds are not achieved due to the engagement failure or the release failure. The area. In addition, a gear ratio region that does not correspond to the command shift speed in other regions is defined as a gear ratio abnormality determination region.

  In this case, if the actual gear ratio exists in the shaded area, it can be determined that a neutral state failure has occurred. However, as a result of monitoring the actual gear ratio, if the actual gear ratio is in the gear ratio abnormality determination range and becomes larger than the gear ratio corresponding to the command gear, the abnormality and the driving force that can secure the driving force Each case includes an abnormality that cannot be secured. In particular, as described above, in the case of an input shaft interlock state / output shaft neutral state failure, the actual gear ratio is increased, so that it is not determined as a neutral state failure.

  Therefore, it is possible to identify an interlock state failure, a neutral state failure, and a gear ratio abnormality failure, and to reliably avoid the failure at the 1st and 2nd speeds where an input shaft interlock state / output shaft neutral state failure can occur. It was decided to shift to a gear stage.

[Shift control when it is determined that the gear ratio is abnormal]
Next, the shift control flow when it is determined that the gear ratio is abnormal by the control flow will be described. FIG. 18 is a flowchart showing the shift control process when it is determined that the gear ratio is abnormal.

  In step 301, it is determined whether or not the command shift stage when the gear ratio abnormality is detected is the first speed when the engine brake range position is selected. If the first gear is the first speed, the process proceeds to step 302. Otherwise, the process proceeds to step 303. .

  In step 302, a third speed command is output as an avoidance shift stage. The avoidance shift speed will be described later.

  In step 303, it is determined whether or not the command shift speed when the gear ratio abnormality is detected is the second speed. If the gear ratio is the second speed, the process proceeds to step 303. Otherwise, the process proceeds to step 304.

  In step 304, a 2.5-speed command is output as an avoidance shift stage. The avoidance shift speed will be described later.

  In step 305, the command shift stage is fixed and the shift is prohibited until the vehicle stops. Basically, when a gear ratio abnormality is detected at gears other than the first and second gears, it is not a failure in the input shaft interlock state and the output shaft neutral state, so the driving force is secured, This is because it is possible to ensure traveling performance by prohibiting the above.

  Next, the operation of the control process will be described. When proceeding to step 106 to step 110, it is basically determined that there is no interlock state failure, and it has been found in step 107 that there is no neutral state failure. At this time, when the actual gear ratio exists in the gear ratio abnormality determination region shown in FIG. 17, the following cases are assumed.

(Specific example 1)
If the direct clutch C2 is in engagement at the time of the 1st speed engagement command while the engine brake range position is selected, the fourth planetary gear G4 rotates integrally as shown in the collinear diagram in FIG. Can be achieved. Further, as shown in the collinear diagram of FIG. 15, an input shaft interlock state / output shaft neutral state failure may occur due to the engagement failure of the 2346 brake B3.

  If the 1.5th speed is achieved simply by engaging failure of the direct clutch C2, there is no particular problem because the driving force is secured, but in the case of the engaging failure of the 2346 brake B3, the driving force can be secured. Not a problem. That is, in the automatic transmission according to the first embodiment, since no hydraulic switch or the like is provided, it is not possible to specify specifically which fastening element is supplied with the hydraulic pressure and the abnormality has occurred. Therefore, it is necessary to surely avoid any abnormality that occurs.

  At this time, since both failures belong to the gear ratio abnormality determination range, the shift speed can be achieved regardless of which failure occurs, and avoidance shift that can secure driving force without a sudden downshift. Shift to 3rd gear as a stage. This is because the third speed is a gear stage that engages both the 2346 brake B3 and the direct clutch C2.

  As a result, even if a gear ratio abnormality is detected, shifting to the third speed as the avoidance shift stage prevents the input shaft interlock state / output shaft neutral state failure and improves driving performance by ensuring driving force. be able to.

(Specific example 2)
If the direct clutch C2 fails in engagement at the time of the second speed command, the fourth planetary gear G4 rotates integrally as shown by the thick dotted line in FIG. 20, and the third speed can be achieved. Further, when the 2346 brake B3 breaks down, the first speed can be achieved as shown by the thick dotted line in the collinear diagram of FIG. Further, as shown in the collinear diagram of FIG. 16, an input shaft interlock state / output shaft neutral state failure may occur due to a fastening failure of the front brake B1.

  If you achieved 3rd speed simply by engaging failure of the direct clutch C2, or 1st speed achieved by 2346 brake B3 disengagement failure, there is no big problem because the driving force is secured. If a gear ratio close to the 1st speed or the 3rd speed is achieved due to the brake failure of the brake B1, the driving force cannot be secured, which is a problem.

  That is, in the automatic transmission according to the first embodiment, since no hydraulic switch or the like is provided, it is not possible to specify specifically which fastening element is supplied with the hydraulic pressure and the abnormality has occurred. Therefore, it is necessary to surely avoid any abnormality that occurs.

  At this time, since any of the above failures belong to the gear ratio abnormality determination range, it is possible to achieve a shift stage that can be achieved regardless of the occurrence of the failure, and avoidance that can secure a driving force without a sudden downshift. Shift to 2.5 speed as a shift stage. Specifically, as shown by the thick line in FIG. 20, the front brake B1, the direct clutch C2, and the H & LR clutch C3 are engaged. In other words, the shift that can be achieved by engaging the direct clutch C2, the front brake B1, and the H & LR clutch C3 regardless of whether the direct clutch C2 is broken, the 2346 brake B3 is broken, or the front brake B1 is broken. Because it is a step.

  As a result, even if a gear ratio abnormality is detected, shifting to 2.5 speed, which is a gear stage that is not normally used as an avoidance gear stage, avoids failures in the input shaft interlock state and the output shaft neutral state. The traveling performance can be improved by securing the driving force.

[Neutral shift stage control process at neutral state failure]
Next, the avoidance shift stage control process when a neutral state failure is detected will be described. As described in the flowchart of FIG. 12, when the actual gear ratio is in the neutral state determination region, it is determined that the neutral state has failed. Hereinafter, the neutral state failure and the avoidance shift stage for each command shift stage will be described. FIG. 21 is a flow chart showing a neutral speed failure avoidance shift stage control process.

(When the command gear is 1st, 2nd, 3rd)
In step 401, it is determined whether the command shift speed is 1st, 2nd, or 3rd. If 1st, 2nd, or 3rd, the process proceeds to step 402. If not, the process proceeds to step 403.

  That is, when the command shift speed is the first speed, the front brake B1 does not slip due to the action of the first one-way clutch F1. Even if the H & LR clutch C3 is slipping, it will not slip if the low brake B2 is engaged. Therefore, in this case, the neutral state failure occurs only when the low brake B2 slips.

  Next, in the case where the command shift speed is the second speed, it is determined that the neutral state has failed when the gear ratio becomes larger than the first speed as shown by the hatched area in FIG. If the 2346 brake B3 is slipping, the gear ratio cannot be smaller than the first speed due to the action of the first one-way clutch F1. Therefore, in this case, the neutral state failure occurs only when the low brake B2 slips.

  Next, in the case where the command shift speed is 3rd speed, it is determined that the neutral state has failed when the gear ratio becomes larger than 1.5th speed as shown by the hatched area in FIG. If the direct clutch C2 is slipping, only the second speed is achieved, and the gear ratio cannot be smaller than the 1.5th speed. Next, when the 2346 brake B3 is slipping, only the 1.5th speed is achieved as shown in FIG. 19, and the gear ratio cannot be smaller than the 1.5th speed. Therefore, in this case, the neutral state failure occurs only when the low brake B2 slips.

  From the above viewpoint, when a neutral state failure is detected in the first speed, the second speed, and the third speed, it can be identified as the slip of the low brake B2. Therefore, at this time, the fourth speed, which is the lowest speed stage not using the low brake B2, is used as the avoidance speed stage.

  (When the command gear is 4th gear)

  In step 403, it is determined whether or not the command shift speed is the fourth speed. If it is the fourth speed, the process proceeds to step 404; otherwise, the process proceeds to step 407.

  In step 404, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 406. Otherwise, the process proceeds to step 405.

  In step 405, the neutral state is set.

  In step 406, the command gear is set to the second speed.

  In the case where the command shift speed is the fourth speed, a neutral state failure is determined when the gear ratio becomes smaller than the 2.5th speed as shown by the hatched area in FIG. If the 2346 brake B3 is slipping, the first one-way clutch F1 acts, so only 2.5 speed is achieved as shown in FIG. 20, and the gear ratio is smaller than 2.5 speed. impossible. Next, regarding the case where the direct clutch C2 is slipping and the case where the H & LR clutch C3 is slipping, the gear ratio may be smaller than the 2.5th speed regardless of which of the two slips.

  Therefore, it cannot be specified as either the direct clutch C2 or the H & LR clutch C3. Therefore, at this time, the neutral state is once set. Then, at the stage where the vehicle speed Vsp has decreased and the possibility of over-rotation of the rotating member has been eliminated, the second speed that does not require the engagement of both the direct clutch C2 and the H & LR clutch C3 is used as an avoidance shift stage.

(When the command gear is 5th gear)
In step 407, it is determined whether or not the command shift speed is the fifth speed. If it is the fifth speed, the process proceeds to step 408. Otherwise, the process proceeds to step 415.

  In step 408, it is determined whether or not the failure location is the H & LR clutch C3. If it is the H & LR clutch C3, the process proceeds to step 409. Otherwise, the process proceeds to step 412.

  In step 409, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 410. Otherwise, the process proceeds to step 411.

  In step 410, a third speed command is output as the command shift stage.

  In step 411, a neutral state is set.

  In step 412, it is determined whether the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 414. Otherwise, the process proceeds to step 413.

  In step 413, a 6-speed command is output as the command shift stage.

In step 414, a second speed command is output as the command shift stage.
When the command shift speed is 5th, the neutral state failure is determined when the gear ratio becomes smaller than 2.5th as shown by the hatched area in FIG. If the input clutch C1 is slipping, only the 2.5th speed is achieved as shown in FIG. 20, and the gear ratio cannot be smaller than the 2.5th speed. Next, when the direct clutch C2 is slipping, as shown in FIG. 22, the rigid lever L2 can rotate around the third ring gear R3 and the fourth carrier PC4, so the gear ratio is smaller than 2.5 speed. Can be. Similarly, when the H & LR clutch C3 is slipping, the rigid lever L23 can rotate around the third ring gear R3 and the fourth carrier PC4 as shown in FIG. 23, so the gear ratio is smaller than 2.5 speed. Can be. At this time, the rigid lever L24 remains horizontal.

  Here, as shown in FIGS. 22 and 23, even in the same neutral state failure, the way of increasing the rotational speed of the fourth ring gear R4 is different. Therefore, it is possible to identify whether the direct clutch C2 is malfunctioning or the H & LR clutch C3 is malfunctioning from the rotational speed difference between the first turbine rotational speed sensor 3 and the second turbine rotational speed sensor 4.

  In case of H & LR clutch C3 failure, it is impossible to avoid other gears. Therefore, when the vehicle speed Vsp falls below the set value Vsp0, avoid to 3rd gear that does not use H & LR clutch C3. .

  On the other hand, in the case of a direct clutch C2 failure, it is possible to avoid the 6th speed by engaging the 2346 brake B3. Therefore, the direct clutch C2 is used when the vehicle speed Vsp falls below the set value Vsp0. Avoid the 2nd speed, which is the gear position that does not.

(When the command gear is 6th gear)
In step 415, it is determined whether or not the command shift speed is 6th speed. If 6th speed, the process proceeds to step 416. Otherwise, the process proceeds to step 423.

  In step 416, it is determined whether or not the failure location is 2346 brake B3. If 2346 brake B3, the process proceeds to step 420. Otherwise, the process proceeds to step 417.

  In step 417, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 419. Otherwise, the process proceeds to step 418.

  In step 418, a 7th speed command is output as the command shift stage.

  In step 419, a 2.5-speed command is output as the command shift stage.

  In step 420, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 422. Otherwise, the process proceeds to step 421.

  In step 421, a neutral state is set.

In step 422, a third speed command is output as the command shift stage.
When the command shift speed is 6th, the neutral state failure is determined when the gear ratio becomes smaller than 5th as shown in the hatched area in FIG. If the 2346 brake B3 is slipping, the rigid lever L1 rotates about the input shaft Input as shown in FIG. 24, and accordingly, the rigid lever L2 rotates about the third ring gear R3 and the fourth carrier PC4. Therefore, the gear ratio may be smaller than that in the fifth speed.

  Next, when the input clutch C1 is slipping, as shown in FIG. 25, since the rigid lever L2 can rotate around the fourth ring gear R4, the gear ratio may be smaller than the fifth speed. Similarly, when the H & LR clutch C3 is slipping, the rigid lever L23 can rotate around the third ring gear R3 and the fourth carrier PC4 as shown in FIG. 26, so the gear ratio becomes smaller than the fifth gear. There can be. At this time, the rigid lever L24 maintains the inclination at the sixth speed.

  Here, as shown in FIGS. 24, 25, and 26, the movement of the rigid lever L1 is completely different even in the same neutral state failure. Therefore, it is possible to specify whether the failure of the 2346 brake B3 or other failure is caused from the difference in the rotational speed between the first turbine rotational speed sensor 3 and the second turbine rotational speed sensor 4.

  In the case of 2346 brake B3 failure, since it is possible to avoid the 7th speed by engaging the front brake B1, it is avoided to the 7th speed, and when the vehicle speed Vsp falls below the set value Vsp0, as shown in FIG. Avoid 2.5-speed, which is the gear position that does not use brake B3.

  On the other hand, in the case of failure other than 2346 brake B3, there is no avoidable shift speed, so the gearbox is in a neutral state and the vehicle speed Vsp falls below the set value Vsp0, and the shift speed does not use the input clutch C1 and the H & LR clutch C3. Avoid to 3rd gear.

(When the command gear is 7th gear)
In step 423, it is determined whether or not the failure location is the front brake B3. If the brake is the front brake B1, the process proceeds to step 424. Otherwise, the process proceeds to step 427.

  In step 424, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 425. Otherwise, the process proceeds to step 426.

  In step 425, a 6-speed command is output as the command shift stage.

  In step 426, a third speed command is output as the command shift stage.

  In step 427, it is determined whether or not the vehicle speed Vsp is less than the set value Vsp0. If it is less than the set value, the process proceeds to step 429. Otherwise, the process proceeds to step 428.

  In step 428, the neutral state is set.

In step 429, a third speed command is output as the command shift stage.
When the command shift speed is 7th speed, it is determined that the neutral state has failed when the gear ratio becomes smaller than 6th speed as shown by the hatched area in FIG. If the front brake B1 is slipping, the rigid lever L1 rotates about the input shaft Input as shown in FIG. 27, and accordingly, the rigid lever L2 rotates about the third ring gear R3 and the fourth carrier PC4. Therefore, the gear ratio may be smaller than that in the fifth speed.

  Next, when the input clutch C1 is slipping, as shown in FIG. 28, since the rigid lever L2 can rotate around the fourth ring gear R4, the gear ratio may be smaller than the fifth speed. Similarly, when the H & LR clutch C3 is slipping, the rigid lever L23 can rotate around the third ring gear R3 and the fourth carrier PC4 as shown in FIG. 29, so the gear ratio becomes smaller than the fifth gear. There can be. At this time, the rigid lever L24 maintains the inclination at the seventh speed.

  Here, as shown in FIGS. 27, 28, and 29, the movement of the rigid lever L1 is completely different even in the same neutral state failure. Therefore, it is possible to specify whether the front brake B1 is in failure or other than that from the rotation speed difference between the first turbine rotation speed sensor 3 and the second turbine rotation speed sensor 4.

  If the front brake B1 is faulty, the 2346 brake B3 can be used to avoid the 6th gear, so avoid the 6th gear and shift the vehicle without using the front brake B1 when the vehicle speed Vsp falls below the set value Vsp0. Avoid 3rd gear, which is the stage.

  On the other hand, in the case of a failure other than the front brake B1, there is no avoidable shift speed, so the gear shifts to the neutral state and the vehicle does not use the input clutch C1 and the H & LR clutch C3 when the vehicle speed Vsp falls below the set value Vsp0. Avoid to 3rd gear.

  As described above, in the case of a neutral state failure, it is possible to widen the range of shift control by including the avoidance shift stage (2.5 speed) that is not used in the engagement / release control law executed in the normal state. , Driving performance can be ensured.

  A map or the like may be mounted in advance based on the above logic, and an avoidance gear stage having a correlation with the state at the time of failure detection may be set in the map.

[Exploration control processing and abnormal speed change control processing]
Next, a description will be given of the search control process and the shift control process at the time of abnormality based on the cause of failure specified by the search control. This control process is executed when the vehicle is temporarily stopped and then restarted after the avoidance shift stage control process, and therefore, it is assumed that some of the fastening elements have a fastening failure. . The abnormal speed change control process is a process in which the speed change control is performed with a logic different from the speed change map or the like used in the normal speed change control process. Avoidance gears are set, and gear control is performed between the three gears using the vehicle speed as a parameter.

FIG. 30 is a flowchart showing the search control process and the abnormal speed shift control process.
In step 500, it is determined whether or not a neutral state failure has occurred. If a neutral state failure has occurred, the process proceeds to step 502. If any other failure has occurred, the process proceeds to step 501.

  In step 501, it is determined whether or not a failed fastening element has already been identified by the failure location identification process shown in FIG. Note that this step may be omitted. When the faulty engagement element has been identified, the process proceeds to step 524, and the abnormal speed shift control corresponding to the failure engagement element is executed. If not specified, the process proceeds to step 506. The abnormal speed change control executed in step 524 is an abnormal speed change control in which, when a failure occurs, a shift is made between three shift speeds determined in advance for each engagement element that has failed. Note that the details of the abnormal speed change control for each failed engagement element are the same as steps 508, 510, 516, 522, and 523, which will be described later, and a description thereof will be omitted.

  In step 502, it is determined whether or not a neutral state failure has occurred in the first speed, second speed, and third speed. If a neutral state failure has occurred in the first speed, second speed, and third speed, the process proceeds to step 503.

  In step 503, the 4th speed, the 5th speed, and the 6th speed are selected as avoidance shift speeds, and the shift control process for abnormal time is executed. That is, as explained in the neutral state failure, the case where the neutral state failure occurs when the command gear is 1st, 2nd, or 3rd can be identified as a release failure of the low brake B2. . Therefore, at this time, the running performance can be improved by securing the driving force by executing the abnormal speed shift control using the 4th speed, the 5th speed, and the 6th speed, which are the speed stages not using the low brake B2.

  In step 504, it is determined whether or not a neutral state failure has occurred at the seventh speed. If a neutral state failure has occurred at the seventh speed, the process proceeds to step 505. Otherwise, the process proceeds to step 506.

  In step 505, 1st speed, 2nd speed, and 3rd speed are selected as avoidance shift speeds, and abnormal speed shift control is executed. That is, as explained in the neutral state failure, the neutral state failure occurs when the command shift speed is the seventh speed when any of the front brake B1, the input clutch C1, and the H & LR clutch C3 is slipping. Occurs. Therefore, it is not necessary to fasten any of the fastening elements (the engine brake does not act). By executing the abnormal speed change control using the first speed, the second speed, and the third speed, driving performance is improved by securing the driving force. Can do.

  In step 506, the first speed (engine brake non-operation) is commanded as the command gear.

  In step 507, it is determined whether or not the actual gear ratio is equivalent to 1.5 speed. If 1.5, the process proceeds to step 508. Otherwise, the process proceeds to step 509.

  In step 508, the 3rd speed, the 4th speed, and the 5th speed are selected as avoidance shift speeds, and the shift control at the time of abnormality is executed. That is, achieving 1.5 speed is achieved by engaging the low brake B2, the first one-way clutch F1, and the direct clutch C2, as shown in FIG. Since the command shift speed is the first speed, since the engagement element is output only to the low brake B2, it can be determined that the engagement failure of the direct clutch C2. It is the 3rd, 4th and 5th speeds that enable shifting while the direct clutch C2 is engaged. Therefore, by executing the abnormal speed shift control using the third speed, the fourth speed, and the fifth speed, it is possible to improve the traveling performance by securing the driving force.

  In step 509, it is determined whether or not the actual gear ratio is equivalent to the second speed. If the second gear is the second speed, the process proceeds to step 510. Otherwise, the process proceeds to step 511.

  In step 510, 2nd speed, 3rd speed, and 4th speed are selected as avoidance shift speeds, and shift control during an abnormality is executed. That is, achieving the second speed is achieved by engaging the low brake B2 and the 2346 brake B3, as shown in the alignment chart of FIG. Since the command shift speed is the first speed, since the engagement element is output only to the low brake B2, it can be determined that the engagement failure of the 2346 brake B3. The second gear, the third gear, the fourth gear, and the sixth gear can be shifted while the 2346 brake B3 is engaged. Since it is only necessary to secure approximately three shift speeds in the abnormal speed change control, the running performance can be improved by securing the driving force by executing the abnormal speed change control using the second speed, the third speed, and the fourth speed. .

  In step 511, it is determined whether or not the vehicle speed Vsp is larger than a preset first set value Vsp1, and if it is larger, the process proceeds to step 512, and otherwise, steps 506 to 509 are repeated. Since the first speed command is a gear shift command for specifying a failure location, it can be sufficiently detected if it is appropriately set to the first set value Vsp1 such as 10 km / h.

  In step 512, the second speed (engine brake non-operation) is commanded as the command gear.

  In step 513, it is determined whether or not the actual gear ratio is equivalent to the first speed. When the first gear is the first speed, the process proceeds to step 514. Otherwise, the process proceeds to step 515.

  In step 514, 1st speed, 2.5th speed, and 5th speed are selected as avoidance shift speeds, and abnormal speed shift control is executed. That is, achieving the first speed is achieved by engaging the low brake B2, as shown in the alignment chart of FIG. Since the command shift speed is the second speed, since it is output to the low brake B2 and the 2346 brake B3 as the engaging elements, it can be determined that the 2346 brake B3 is released. Shifts that do not require the engagement of the 2346 brake B3 are 1st, 2.5th, 5th, and 7th. Since it is only necessary to secure about 3 shift speeds in the abnormal speed change control, the running performance is improved by securing the driving force by executing the abnormal speed change control using the first speed, the 2.5 speed, and the fifth speed. Can do. In this case, the speed change control uses the 2.5th speed, which is not used in the normal speed change control, to ensure traveling performance.

  In step 515, it is determined whether or not the actual gear ratio is equivalent to the second speed. If the second gear is the second speed, the process proceeds to step 517. Otherwise, the process proceeds to step 516.

  In step 516, the 1st speed, 2.5th speed, and 7th speed are selected as the avoidance shift speeds, and the abnormal speed shift control is executed. That is, achieving a gear ratio that is neither the first speed nor the second speed means that both the front brake B1 and 2346 brake B3 are engaged and the input shaft interlock state / output as shown in the alignment chart of FIG. This is considered to be an axial neutral state. Since the command shift speed is the second speed, since the engagement elements are output to the low brake B2 and the 2346 brake B3, it can be determined that the engagement failure of the front brake B1. The first speed, the 2.5th speed, and the seventh speed enable gear shifting while the front brake B1 is engaged. Therefore, by executing the abnormal speed shift control using the first speed, the 2.5th speed, and the seventh speed, the traveling performance can be improved by securing the driving force. In this case, the speed change control uses the 2.5th speed, which is not used in the normal speed change control, to ensure traveling performance.

  In step 517, it is determined whether or not the vehicle speed Vsp is greater than a preset second set value Vsp2. If it is greater, the process proceeds to step 518, and otherwise, steps 512 to 517 are repeated. Since the concept of this step is the same as that of step 511, description thereof is omitted.

  In step 518, the third speed is commanded as the command gear.

  In step 519, it is determined whether or not the actual gear ratio is equivalent to the second speed. If the second gear is the second speed, the process proceeds to step 520. Otherwise, the process proceeds to step 521.

  In step 520, 1st speed, 2nd speed, and 6th speed are selected as avoidance shift speeds, and abnormal speed shift control is executed. That is, achieving the second speed is achieved by engaging the low brake B2 and the 2346 brake B3, as shown in the alignment chart of FIG. Since the command shift speed is the third speed, since the engagement elements are output to the low brake B2, 2346 brake B3, and direct clutch C3, it can be determined that the direct clutch C3 is disengaged. The first speed, the second speed, the sixth speed, and the seventh speed enable gear shifting that does not require the engagement of the direct clutch C3. Since it is only necessary to secure approximately three shift speeds in the abnormal speed change control, running performance can be improved by securing the driving force by executing the abnormal speed change control using the first speed, the second speed, and the sixth speed. .

  In step 521, it is determined whether or not the actual gear ratio is equivalent to the third speed. When the third gear is the third speed, the process proceeds to step 523, and otherwise, the process proceeds to step 522.

  In step 522, 1st speed, 2nd speed, and 2.5th speed are selected as avoidance shift speeds, and the shift control at abnormal time is executed. That is, if a gear ratio that is neither the second speed nor the third speed is achieved, the neutral state failure at the third speed is eliminated in step 502, and thus it is considered that a gear ratio abnormality due to the interlock state has occurred. Interlocking can occur at the 3rd speed because of the failure of the front brake B1 and the failure of the H & LR clutch C3. However, since the engagement failure of the front brake B1 has already been eliminated in step 516, it can be determined that the engagement failure of the H & LR clutch C3.

  The first, second, fourth, fifth, sixth, seventh and 2.5th speeds can be changed while the H & LR clutch C3 is kept engaged. Since it is only necessary to secure about 3 shift speeds in the abnormal speed change control, the running performance is improved by securing the driving force by executing the abnormal speed change control using the first speed, the second speed, and the 2.5 speed. Can do.

  In step 523, 1st speed, 2nd speed, and 3rd speed are selected as avoidance shift speeds, and abnormal speed shift control is executed. That is, by the above steps, low brake B2 engagement / release failure, direct clutch C2 engagement / release failure, 2346 brake B3 engagement / release failure, front brake B1 engagement failure, and H & LR clutch C3 engagement failure are possible. All sex is excluded. Therefore, although it has not been possible to specify in all of the fastening elements what kind of failure has occurred, there is no problem when achieving the first speed, the second speed, and the third speed. Therefore, by performing the abnormal speed change control using the first speed, the second speed, and the third speed, the traveling performance can be improved by securing the driving force.

  Basically, after detecting the interlock state, the actual gear ratio of the gear stage that is achieved when the fastening element is released is detected, and therefore, at this stage, which fastening element has failed in fastening is specified. However, if the driving wheel is stopped before the actual gear ratio is detected when the interlock state is detected during sudden braking, for example, when the driving wheel is locked by full braking, the actual gear ratio cannot be detected. There is a fear. Therefore, when it is determined in step 501 that it has not been specified, the search control process is executed when the vehicle restarts after the vehicle stops in order to reliably determine the fastening element that has failed.

As described above, the effects listed below can be obtained in the first embodiment.
(1) When one of the engaging elements detects an interlocking state in which one of the engaging elements fails to engage and the rotation of the input shaft (Input) and the output shaft (Output) is fixed, one of the engaging elements that achieves the command shift stage at this point Is released from the command gear position at the time when the interlock state is detected, and it is determined whether or not an avoidance gear position that does not involve a significant downshift is achievable. The gear was shifted to the gear stage, and the neutral state was set at other times.

  Therefore, when it is possible to achieve an avoidance shift stage that does not involve a significant downshift, it is possible to secure driving force by achieving the avoidance shift stage while avoiding an interlock state failure, improving the running performance Can be achieved. Further, by achieving the avoidance shift stage by simply releasing one engagement element, it is possible to achieve a highly robust failure time control process.

  (2) The avoiding shift stage includes a shift stage that is not used in the engagement / release control law that is executed by the shift control means in a normal state. Specifically, it was decided to use 1.5 speed or 2.5 speed. As a result, a plurality of avoiding shift speeds can be ensured regardless of the command shift speed where the interlock state occurs.

  (3) If the gear position higher than the second speed, which is the predetermined gear position, cannot be reliably achieved, the vehicle is brought into a neutral state due to a significant downshift, and the detected vehicle speed is less than the set value. When this happens, the fastening element (low brake B2) that is fastened at the forward low speed stage is fastened normally, and the avoidance speed stage is achieved by two of the fastening elements that have failed to fasten. Therefore, when the vehicle speed is higher than the predetermined vehicle speed, the neutral state is temporarily set to avoid the interlock state, and the vehicle speed Vsp becomes lower than the set value, so that the over-rotation of the rotating element and the excessive engine braking action do not work due to the downshift. Since the avoidance shift stage is ensured at the stage, the driving force can be secured safely.

  (4) The avoiding shift stage includes a shift stage (1.5 speed) that is not used in the engagement / release control law executed by the shift control means at normal times. Therefore, even if any fastening element has a fastening failure, the driving force can be reliably ensured.

  (5) The vehicle is stopped after the interlock state is detected, and at the time of subsequent restart, a search control process for determining the fastening element that has failed is executed. Therefore, with the sudden stop of the vehicle, the actual gear ratio cannot be detected after the interlock state is detected, and the fastening failure location can be reliably determined even when the fastening element having the fastening failure cannot be determined.

  (6) When an interlock state is detected, one of the fastening elements that achieves the command shift stage at this point is released, thereby causing a significant downshift from the command shift stage when the interlock state is detected. The first shift speed group (4, 5, 6, 7th speed) that can achieve the avoidance shift speed is classified into the second shift speed group (1, 2, 3 speed) that cannot be achieved.

  The first engagement element (low brake B2) that is released when the first gear group (4, 5, 6, and 7th speed) and the second engagement stage (1, 2, 3rd gear) are released. The first engagement element is provided in an oil passage that supplies the engagement pressure of the second engagement element (input clutch C1) to be operated and the command shift speed is the first shift speed group (4th, 5, 6, 7th speed). First switching that disables the supply of the engagement pressure of (low brake B2) and disables the supply of the engagement pressure of the second engagement element (input clutch C1) in the second gear group (1, 2 and 3rd speed) When the valve SV1 and the interlock state are detected, the command shift stage at this time is the first shift stage group (4, 5, 6, 7th speed) and the second shift stage group (1, 2, 3rd speed). Different interlock avoidance control is executed based on which one belongs.

  Thus, by providing a common switching valve for each fastening element to be released in each gear group, the possibility of a fastening failure of the first fastening element or the second fastening element is eliminated, and the interlock state is Different interlock avoidance control is executed based on the generated gear group. In this way, by not performing the uniform failure time control regardless of the shift speed at which the engagement element is generated, it is possible to execute appropriate control according to the state at the time of the failure.

  Specifically, in the case of the first gear group (4th, 5th, 6th and 7th speeds), the fastening element corresponding to the command gear stage is released, and in the case of the second gear stage group (1, 2nd, 3rd speed). Was once in the neutral state, and then the low brake B2 was engaged when the vehicle speed was below the set value.

  That is, the low brake B2 is engaged only at the first, second, and third speeds, and the input clutch C1 is engaged only at the fifth, sixth, and seventh speeds. If the possibility of low brake B2 engagement failure cannot be ruled out at the 4th, 5th, 6th, and 7th speeds, if a low brake B2 engagement failure occurs, even if one engagement element is released, the predetermined speed change There is a possibility that a significant downshift may be caused by the shift speed lower than the shift speed. On the other hand, in the first embodiment, in the fourth speed, the fifth speed, the sixth speed, and the seventh speed, the first switching valve SV1 eliminates the possibility of the failure of the low brake B2 being engaged, so that only one engaging element is released. Thus, it is possible to achieve the avoidance shift speed, reliably avoiding the interlock state, obtain driving force without a significant downshift, and ensure traveling performance.

  Also, between 1st speed, 2nd speed and 3rd speed, after all the engagement elements are released once, the vehicle brake is configured to engage the low brake B2 only when the vehicle speed Vsp becomes less than the set value. As a result, it is possible to prevent a sudden braking force from being generated on the drive wheels, and to secure the drive force before the vehicle stops.

1 is a skeleton diagram showing a configuration of an automatic transmission that achieves FR type 7 forward speed 1 reverse speed according to Embodiment 1; FIG. FIG. 3 is a circuit diagram illustrating a hydraulic circuit of the control valve unit according to the first embodiment. 2 is a schematic diagram illustrating a configuration of a pressure regulating valve according to Embodiment 1. FIG. FIG. 3 is a schematic diagram illustrating a configuration of a first switching valve according to the first embodiment. 3 is a schematic diagram illustrating a configuration of a second switching valve according to Embodiment 1. FIG. FIG. 3 is a schematic diagram illustrating a configuration of a third switching valve according to the first embodiment. FIG. 4 is a schematic diagram illustrating a configuration of a fourth switching valve according to the first embodiment. It is a figure which shows the fastening operation | movement table | surface of the forward 7 speed reverse speed 1 in the automatic transmission of Example 1. FIG. FIG. 6 is a collinear diagram illustrating a rotation stop state of members at each of the seventh forward speed and the reverse first speed in the automatic transmission according to the first embodiment. It is a figure showing the action | operation table | surface of solenoid valve SOL1-SOL7 in each gear stage of Example 1. FIG. 3 is a flowchart illustrating a failure detection process according to the first embodiment. 3 is a flowchart illustrating an abnormality detection control process according to the first embodiment. 6 is a flowchart illustrating an avoidance shift speed control process when it is determined that the interlock state has failed in the first embodiment. It is a figure showing the gear stage achieved in the relationship of the fastening failure element with respect to the command gear stage of Example 1, and the released fastening element. It is a figure showing the change of a collinear chart when the fastening failure generate | occur | produces in 2346 brake at the time of 1st speed driving | running | working of Example 1. FIG. It is a figure showing the change of an alignment chart at the time of the 2nd speed driving | running | working of Example 1 when a fastening failure generate | occur | produces in the front brake. It is a figure showing the relationship between the command gear stage of Example 1, and the gear stage which can be achieved when a failure generate | occur | produces in the command gear stage. 6 is a flowchart illustrating a shift control process when it is determined that the gear ratio is abnormal in the first embodiment. FIG. 3 is a collinear diagram showing a first speed in Example 1. FIG. 3 is a collinear diagram illustrating 2.5 speed according to the first embodiment. 6 is a flowchart showing a neutral state failure avoidance shift stage control process according to the first embodiment. It is a figure showing the change of the alignment chart at the time of the neutral state failure in the 5th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in the 5th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 6th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 6th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 6th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 7th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 7th speed of Example 1. FIG. It is a figure showing the change of the alignment chart at the time of the neutral state failure in 7th speed of Example 1. FIG. 3 is a flowchart illustrating a search control process and an abnormal speed shift control process according to the first embodiment.

Explanation of symbols

GS1 1st planetary gear set
GS2 2nd planetary gear set
G1 1st planetary gear
G2 2nd planetary gear
G3 3rd planetary gear
G4 4th planetary gear
M1 first linked member
M2 second linked member
M3 Third linked member
C1 input clutch
C2 direct clutch
C3 H & LR clutch
B1 Front brake
B2 Low brake
B3 2346 brake
B4 Reverse brake
F1 1st one-way clutch
F2 2nd one-way clutch
Input Input axis
Output Output shaft 1 Accelerator pedal operation amount sensor 2 Engine speed sensor 3 First turbine speed sensor 4 Second turbine speed sensor 5 Output shaft speed sensor 6 Inhibitor switch
CVU control valve unit
Eg engine
OP Oil pump
PV pilot valve
CV1-CV6 Pressure regulating valve
SOL1-SOL7 solenoid valve
SV1-SV4 selector valve
TC torque converter

Claims (6)

A planetary gear train having an input rotating element coupled to the power source, an output rotating element coupled to the drive wheel, and a plurality of rotating elements;
A plurality of fastening elements for fastening or releasing between the rotating elements or selectively stopping the rotating elements;
Shift control means for determining a command shift stage based on a running state and executing a fastening / release control law of the fastening element;
In an automatic transmission control device comprising:
An interlock state detection means for detecting an interlock state in which one of the fastening elements is fastened to failure and rotation of the input rotation element and rotation of the output rotation element are fixed;
When the interlock state is detected by the interlock state detecting means, one of the fastening elements that achieves the command shift stage at this time is released, so that the shift stage on the higher speed side than the predetermined shift stage is avoided. Avoidance determination means for determining whether it can be achieved from the command shift stage at the time of detecting the interlock state,
When the avoidance determining means determines that it can be achieved, shifting to the avoidance shift stage, otherwise, a failure-time shift control means for setting a neutral state;
A control device for an automatic transmission, characterized by comprising: The control apparatus for an automatic transmission according to claim 1,
2. The automatic transmission control apparatus according to claim 1, wherein the avoiding gear stage includes a gear stage that is not used in an engagement / release control law that is executed in the gear shift control means when it is normal. The control apparatus for an automatic transmission according to claim 1 or 2,
Vehicle speed detecting means for detecting the vehicle speed is provided;
When the vehicle speed change control means is in a neutral state and the detected vehicle speed is less than a set value, a fastening element that is fastened at a forward low speed is normally fastened, and the fastening failure A control device for an automatic transmission, characterized in that an avoidance shift stage is achieved by two. The control device for an automatic transmission according to claim 3,
2. The automatic transmission control apparatus according to claim 1, wherein the avoiding gear stage includes a gear stage that is not used in an engagement / release control law that is executed in the gear shift control means when it is normal. The control apparatus for an automatic transmission according to any one of claims 1 to 4,
A control apparatus for an automatic transmission, comprising: a search control means for stopping a vehicle after an interlock state is detected by the interlock state detection means and determining a fastening element that has failed in a subsequent restart. . An input rotating element coupled to the power source, an output rotating element coupled to the drive wheel, and a planetary gear train having a plurality of rotating elements;
A plurality of fastening elements for fastening or releasing between the rotating elements or selectively stopping the rotating elements;
Shift control means for determining a command shift stage based on a running state and executing a fastening / release control law of the fastening element;
In an automatic transmission control device comprising:
An interlock state detection means for detecting an interlock state in which one of the fastening elements is fastened to failure and rotation of the input rotation element and rotation of the output rotation element are fixed;
When the interlock state is detected by the interlock state detecting means, one of the fastening elements that achieves the command shift stage at this time is released, thereby achieving a shift stage at a higher speed than the predetermined shift stage as an avoidance shift stage. When the possible gear group is defined as the first gear group and the unachievable gear group is defined as the second gear group,
Provided in a fastening pressure supply oil passage of a first fastening element that is released when the first gear group and a second fastening element that is released when the second gear group, and the command gear stage is the first gear stage. A switching valve that disables the supply of the fastening pressure of the first fastening element when in the group, and cannot supply the fastening pressure of the second fastening element when in the second shift stage group;
When the interlock state is detected by the interlock state detection means, different interlock avoidance control is performed based on whether the command shift stage at this time belongs to the first shift stage group or the second shift stage group. Interlock avoidance control means for executing
A control device for an automatic transmission, characterized by comprising:

Images